diff --git a/plugins/sudoers/Makefile.in b/plugins/sudoers/Makefile.in
index 74e7bd92e..227331504 100644
--- a/plugins/sudoers/Makefile.in
+++ b/plugins/sudoers/Makefile.in
@@ -218,7 +218,7 @@ $(devdir)/gram.c $(devdir)/gram.h: $(srcdir)/gram.y
 	    else \
 		gram_y="$(srcdir)/gram.y"; \
 	    fi; \
-	    cmd='$(YACC) -d '"$$gram_y"'; echo "#include <config.h>" > $(devdir)/gram.c; sed "s/^\\(#line .*\\) \"y\\.tab\\.c\"/\1 \"gram.c\"/" y.tab.c >> $(devdir)/gram.c; rm -f y.tab.c; mv -f y.tab.h $(devdir)/gram.h'; \
+	    cmd='$(YACC) -d -p sudoers '"$$gram_y"'; echo "#include <config.h>" > $(devdir)/gram.c; sed "s/^\\(#line .*\\) \"y\\.tab\\.c\"/\1 \"gram.c\"/" y.tab.c >> $(devdir)/gram.c; rm -f y.tab.c; mv -f y.tab.h $(devdir)/gram.h'; \
 	    echo "$$cmd"; eval $$cmd; \
 	fi
 
@@ -229,7 +229,7 @@ $(devdir)/toke.c: $(srcdir)/toke.l
 	    else \
 		toke_l="$(srcdir)/toke.l"; \
 	    fi; \
-	    cmd='$(FLEX) '"$$toke_l"'; echo "#include <config.h>" > $(devdir)/toke.c; cat lex.yy.c >> $(devdir)/toke.c; rm -f lex.yy.c'; \
+	    cmd='$(FLEX) '"$$toke_l"'; echo "#include <config.h>" > $(devdir)/toke.c; cat lex.sudoers.c >> $(devdir)/toke.c; rm -f lex.sudoers.c'; \
 	    echo "$$cmd"; eval $$cmd; \
 	fi
 
diff --git a/plugins/sudoers/gram.c b/plugins/sudoers/gram.c
index 7de57f8cf..63d6d04a0 100644
--- a/plugins/sudoers/gram.c
+++ b/plugins/sudoers/gram.c
@@ -9,7 +9,33 @@
 #define yyclearin (yychar=(YYEMPTY))
 #define yyerrok (yyerrflag=0)
 #define YYRECOVERING() (yyerrflag!=0)
-#define YYPREFIX "yy"
+#define yyparse sudoersparse
+#define yylex sudoerslex
+#define yyerror sudoerserror
+#define yychar sudoerschar
+#define yyval sudoersval
+#define yylval sudoerslval
+#define yydebug sudoersdebug
+#define yynerrs sudoersnerrs
+#define yyerrflag sudoerserrflag
+#define yyss sudoersss
+#define yysslim sudoerssslim
+#define yyssp sudoersssp
+#define yyvs sudoersvs
+#define yyvsp sudoersvsp
+#define yystacksize sudoersstacksize
+#define yylhs sudoerslhs
+#define yylen sudoerslen
+#define yydefred sudoersdefred
+#define yydgoto sudoersdgoto
+#define yysindex sudoerssindex
+#define yyrindex sudoersrindex
+#define yygindex sudoersgindex
+#define yytable sudoerstable
+#define yycheck sudoerscheck
+#define yyname sudoersname
+#define yyrule sudoersrule
+#define YYPREFIX "sudoers"
 #line 2 "gram.y"
 /*
  * Copyright (c) 1996, 1998-2005, 2007-2012
@@ -146,7 +172,7 @@ typedef union {
     int tok;
 } YYSTYPE;
 #endif /* YYSTYPE_DEFINED */
-#line 149 "gram.c"
+#line 175 "gram.c"
 #define COMMAND 257
 #define ALIAS 258
 #define DEFVAR 259
@@ -183,9 +209,9 @@ typedef union {
 #define MYSELF 290
 #define YYERRCODE 256
 #if defined(__cplusplus) || defined(__STDC__)
-const short yylhs[] =
+const short sudoerslhs[] =
 #else
-short yylhs[] =
+short sudoerslhs[] =
 #endif
 	{                                        -1,
     0,    0,   28,   28,   29,   29,   29,   29,   29,   29,
@@ -201,9 +227,9 @@ short yylhs[] =
    14,   14,   15,   15,   15,
 };
 #if defined(__cplusplus) || defined(__STDC__)
-const short yylen[] =
+const short sudoerslen[] =
 #else
-short yylen[] =
+short sudoerslen[] =
 #endif
 	{                                         2,
     0,    1,    1,    2,    1,    2,    2,    2,    2,    2,
@@ -219,9 +245,9 @@ short yylen[] =
     1,    2,    1,    1,    1,
 };
 #if defined(__cplusplus) || defined(__STDC__)
-const short yydefred[] =
+const short sudoersdefred[] =
 #else
-short yydefred[] =
+short sudoersdefred[] =
 #endif
 	{                                      0,
     0,   94,   96,   97,   98,    0,    0,    0,    0,    0,
@@ -242,9 +268,9 @@ short yydefred[] =
    63,   64,   65,   66,   67,   68,   69,   70,   36,
 };
 #if defined(__cplusplus) || defined(__STDC__)
-const short yydgoto[] =
+const short sudoersdgoto[] =
 #else
-short yydgoto[] =
+short sudoersdgoto[] =
 #endif
 	{                                      18,
   104,  105,   27,   28,   44,   45,   46,   35,   61,   37,
@@ -253,9 +279,9 @@ short yydgoto[] =
    48,   51,   57,   49,   52,   58,   55,
 };
 #if defined(__cplusplus) || defined(__STDC__)
-const short yysindex[] =
+const short sudoerssindex[] =
 #else
-short yysindex[] =
+short sudoerssindex[] =
 #endif
 	{                                    541,
  -270,    0,    0,    0,    0,  -21,   -5,  553,  553,   20,
@@ -275,9 +301,9 @@ short yysindex[] =
  -169, -168,  569,    0,    0,    0,    0,    0,    0,    0,
     0,    0,    0,    0,    0,    0,    0,    0,    0,};
 #if defined(__cplusplus) || defined(__STDC__)
-const short yyrindex[] =
+const short sudoersrindex[] =
 #else
-short yyrindex[] =
+short sudoersrindex[] =
 #endif
 	{                                     96,
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
@@ -297,9 +323,9 @@ short yyrindex[] =
     0,    0,    0,    0,    0,    0,    0,    0,    0,    0,
     0,    0,    0,    0,    0,    0,    0,    0,    0,};
 #if defined(__cplusplus) || defined(__STDC__)
-const short yygindex[] =
+const short sudoersgindex[] =
 #else
-short yygindex[] =
+short sudoersgindex[] =
 #endif
 	{                                      0,
   -11,    0,   39,   12,   66,  -72,   27,   76,   -4,   40,
@@ -309,9 +335,9 @@ short yygindex[] =
 };
 #define YYTABLESIZE 932
 #if defined(__cplusplus) || defined(__STDC__)
-const short yytable[] =
+const short sudoerstable[] =
 #else
-short yytable[] =
+short sudoerstable[] =
 #endif
 	{                                      26,
    19,   26,   36,   94,   41,   34,   38,   39,   26,   24,
@@ -410,9 +436,9 @@ short yytable[] =
    50,   50,
 };
 #if defined(__cplusplus) || defined(__STDC__)
-const short yycheck[] =
+const short sudoerscheck[] =
 #else
-short yycheck[] =
+short sudoerscheck[] =
 #endif
 	{                                      33,
     0,   33,    7,   76,   33,   33,    8,    9,   33,  280,
@@ -517,9 +543,9 @@ short yycheck[] =
 #define YYMAXTOKEN 290
 #if YYDEBUG
 #if defined(__cplusplus) || defined(__STDC__)
-const char * const yyname[] =
+const char * const sudoersname[] =
 #else
-char *yyname[] =
+char *sudoersname[] =
 #endif
 	{
 "end-of-file",0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
@@ -536,9 +562,9 @@ char *yyname[] =
 "RUNASALIAS","ERROR","TYPE","ROLE","PRIVS","LIMITPRIVS","MYSELF",
 };
 #if defined(__cplusplus) || defined(__STDC__)
-const char * const yyrule[] =
+const char * const sudoersrule[] =
 #else
-char *yyrule[] =
+char *sudoersrule[] =
 #endif
 	{"$accept : file",
 "file :",
@@ -876,7 +902,7 @@ init_parser(const char *path, bool quiet)
 
     debug_return;
 }
-#line 827 "gram.c"
+#line 853 "gram.c"
 /* allocate initial stack or double stack size, up to YYMAXDEPTH */
 #if defined(__cplusplus) || defined(__STDC__)
 static int yygrowstack(void)
@@ -1716,7 +1742,7 @@ case 105:
 			    yyval.member = new_member(yyvsp[0].string, WORD);
 			}
 break;
-#line 1667 "gram.c"
+#line 1693 "gram.c"
     }
     yyssp -= yym;
     yystate = *yyssp;
diff --git a/plugins/sudoers/gram.h b/plugins/sudoers/gram.h
index 44f9bfd2a..47272b4ea 100644
--- a/plugins/sudoers/gram.h
+++ b/plugins/sudoers/gram.h
@@ -48,4 +48,4 @@ typedef union {
     int tok;
 } YYSTYPE;
 #endif /* YYSTYPE_DEFINED */
-extern YYSTYPE yylval;
+extern YYSTYPE sudoerslval;
diff --git a/plugins/sudoers/parse.c b/plugins/sudoers/parse.c
index 99c96012e..7172ea9a3 100644
--- a/plugins/sudoers/parse.c
+++ b/plugins/sudoers/parse.c
@@ -68,7 +68,7 @@ struct sudo_nss sudo_nss_file = {
 /*
  * Parser externs.
  */
-extern FILE *yyin;
+extern FILE *sudoersin;
 extern char *errorfile;
 extern int errorlineno;
 extern bool parse_error;
@@ -100,7 +100,7 @@ sudo_file_close(struct sudo_nss *nss)
     if (nss->handle != NULL) {
 	fclose(nss->handle);
 	nss->handle = NULL;
-	yyin = NULL;
+	sudoersin = NULL;
     }
     debug_return_int(0);
 }
@@ -117,8 +117,8 @@ sudo_file_parse(struct sudo_nss *nss)
 	debug_return_int(-1);
 
     init_parser(sudoers_file, false);
-    yyin = nss->handle;
-    if (yyparse() != 0 || parse_error) {
+    sudoersin = nss->handle;
+    if (sudoersparse() != 0 || parse_error) {
 	if (errorlineno != -1) {
 	    log_error(0, _("parse error in %s near line %d"),
 		errorfile, errorlineno);
diff --git a/plugins/sudoers/regress/parser/check_fill.c b/plugins/sudoers/regress/parser/check_fill.c
index e0f39214f..d1132bf44 100644
--- a/plugins/sudoers/regress/parser/check_fill.c
+++ b/plugins/sudoers/regress/parser/check_fill.c
@@ -54,7 +54,7 @@
 
 sudo_conv_t sudo_conv;		/* NULL in non-plugin */
 
-YYSTYPE yylval;
+YYSTYPE sudoerslval;
 
 struct fill_test {
     const char *input;
@@ -106,8 +106,8 @@ check_fill(const char *input, int len, int addspace, const char *expect, char **
 {
     if (!fill(input, len))
 	return -1;
-    *resultp = yylval.string;
-    return !strcmp(yylval.string, expect);
+    *resultp = sudoerslval.string;
+    return !strcmp(sudoerslval.string, expect);
 }
 
 static int
@@ -115,8 +115,8 @@ check_fill_cmnd(const char *input, int len, int addspace, const char *expect, ch
 {
     if (!fill_cmnd(input, len))
 	return -1;
-    *resultp = yylval.command.cmnd;
-    return !strcmp(yylval.command.cmnd, expect);
+    *resultp = sudoerslval.command.cmnd;
+    return !strcmp(sudoerslval.command.cmnd, expect);
 }
 
 static int
@@ -124,8 +124,8 @@ check_fill_args(const char *input, int len, int addspace, const char *expect, ch
 {
     if (!fill_args(input, len, addspace))
 	return -1;
-    *resultp = yylval.command.args;
-    return !strcmp(yylval.command.args, expect);
+    *resultp = sudoerslval.command.args;
+    return !strcmp(sudoerslval.command.args, expect);
 }
 
 static int
@@ -191,7 +191,7 @@ cleanup(int gotsig)
 
 /* STUB */
 void
-yyerror(const char *s)
+sudoerserror(const char *s)
 {
     return;
 }
diff --git a/plugins/sudoers/sudoers.h b/plugins/sudoers/sudoers.h
index 0dd061fe1..d6b4463f3 100644
--- a/plugins/sudoers/sudoers.h
+++ b/plugins/sudoers/sudoers.h
@@ -221,7 +221,7 @@ struct timeval;
 /*
  * Function prototypes
  */
-#define YY_DECL int yylex(void)
+#define YY_DECL int sudoerslex(void)
 
 /* goodpath.c */
 bool sudo_goodpath(const char *, struct stat *);
@@ -259,7 +259,7 @@ void restore_perms(void);
 int pam_prep_user(struct passwd *);
 
 /* gram.y */
-int yyparse(void);
+int sudoersparse(void);
 
 /* toke.l */
 YY_DECL;
diff --git a/plugins/sudoers/testsudoers.c b/plugins/sudoers/testsudoers.c
index 148dd6e53..41856d1df 100644
--- a/plugins/sudoers/testsudoers.c
+++ b/plugins/sudoers/testsudoers.c
@@ -124,7 +124,7 @@ extern int optind;
 extern char *malloc_options;
 #endif
 #ifdef YYDEBUG
-extern int yydebug;
+extern int sudoersdebug;
 #endif
 
 int
@@ -143,7 +143,7 @@ main(int argc, char *argv[])
     malloc_options = "AFGJPR";
 #endif
 #ifdef YYDEBUG
-    yydebug = 1;
+    sudoersdebug = 1;
 #endif
 
 #if !defined(HAVE_GETPROGNAME) && !defined(HAVE___PROGNAME)
@@ -270,7 +270,7 @@ main(int argc, char *argv[])
     /* Allocate space for data structures in the parser. */
     init_parser("sudoers", false);
 
-    if (yyparse() != 0 || parse_error) {
+    if (sudoersparse() != 0 || parse_error) {
 	parse_error = true;
 	if (errorlineno != -1)
 	    (void) printf("Parse error in %s near line %d",
diff --git a/plugins/sudoers/toke.c b/plugins/sudoers/toke.c
index 6dfe12c54..cc3999f2f 100644
--- a/plugins/sudoers/toke.c
+++ b/plugins/sudoers/toke.c
@@ -1,4 +1,21 @@
 #include <config.h>
+#define yy_create_buffer sudoers_create_buffer
+#define yy_delete_buffer sudoers_delete_buffer
+#define yy_scan_buffer sudoers_scan_buffer
+#define yy_scan_string sudoers_scan_string
+#define yy_scan_bytes sudoers_scan_bytes
+#define yy_flex_debug sudoers_flex_debug
+#define yy_init_buffer sudoers_init_buffer
+#define yy_flush_buffer sudoers_flush_buffer
+#define yy_load_buffer_state sudoers_load_buffer_state
+#define yy_switch_to_buffer sudoers_switch_to_buffer
+#define yyin sudoersin
+#define yyleng sudoersleng
+#define yylex sudoerslex
+#define yyout sudoersout
+#define yyrestart sudoersrestart
+#define yytext sudoerstext
+
 /*	$OpenBSD: flex.skl,v 1.11 2010/08/04 18:24:50 millert Exp $	*/
 
 /* A lexical scanner generated by flex */
@@ -1468,7 +1485,7 @@ char *yytext;
 #include "lbuf.h"
 #include "secure_path.h"
 
-extern YYSTYPE yylval;
+extern YYSTYPE sudoerslval;
 extern bool parse_error;
 extern bool sudoers_warnings;
 int sudolineno;
@@ -1495,7 +1512,7 @@ int (*trace_print)(const char *msg) = sudoers_trace_print;
 	return (n);		\
 } while (0)
 
-#define ECHO	ignore_result(fwrite(yytext, yyleng, 1, yyout))
+#define ECHO	ignore_result(fwrite(sudoerstext, sudoersleng, 1, sudoersout))
 
 #define	push_include(_p)	(_push_include((_p), false))
 #define	push_includedir(_p)	(_push_include((_p), true))
@@ -1511,7 +1528,7 @@ int (*trace_print)(const char *msg) = sudoers_trace_print;
 
 #define INSTR 5
 
-#line 1514 "lex.yy.c"
+#line 1531 "lex.sudoers.c"
 
 /* Macros after this point can all be overridden by user definitions in
  * section 1.
@@ -1665,9 +1682,9 @@ YY_DECL
 	register char *yy_cp, *yy_bp;
 	register int yy_act;
 
-#line 132 "toke.l"
+#line 133 "toke.l"
 
-#line 1670 "lex.yy.c"
+#line 1687 "lex.sudoers.c"
 
 	if ( yy_init )
 		{
@@ -1753,7 +1770,7 @@ do_action:	/* This label is used only to access EOF actions. */
 
 case 1:
 YY_RULE_SETUP
-#line 133 "toke.l"
+#line 134 "toke.l"
 {
 			    LEXTRACE(", ");
 			    LEXRETURN(',');
@@ -1761,16 +1778,16 @@ YY_RULE_SETUP
 	YY_BREAK
 case 2:
 YY_RULE_SETUP
-#line 138 "toke.l"
+#line 139 "toke.l"
 BEGIN STARTDEFS;
 	YY_BREAK
 case 3:
 YY_RULE_SETUP
-#line 140 "toke.l"
+#line 141 "toke.l"
 {
 			    BEGIN INDEFS;
 			    LEXTRACE("DEFVAR ");
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXRETURN(DEFVAR);
 			}
@@ -1778,7 +1795,7 @@ YY_RULE_SETUP
 
 case 4:
 YY_RULE_SETUP
-#line 149 "toke.l"
+#line 150 "toke.l"
 {
 			    BEGIN STARTDEFS;
 			    LEXTRACE(", ");
@@ -1787,7 +1804,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 5:
 YY_RULE_SETUP
-#line 155 "toke.l"
+#line 156 "toke.l"
 {
 			    LEXTRACE("= ");
 			    LEXRETURN('=');
@@ -1795,7 +1812,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 6:
 YY_RULE_SETUP
-#line 160 "toke.l"
+#line 161 "toke.l"
 {
 			    LEXTRACE("+= ");
 			    LEXRETURN('+');
@@ -1803,7 +1820,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 7:
 YY_RULE_SETUP
-#line 165 "toke.l"
+#line 166 "toke.l"
 {
 			    LEXTRACE("-= ");
 			    LEXRETURN('-');
@@ -1811,20 +1828,20 @@ YY_RULE_SETUP
 	YY_BREAK
 case 8:
 YY_RULE_SETUP
-#line 170 "toke.l"
+#line 171 "toke.l"
 {
 			    LEXTRACE("BEGINSTR ");
-			    yylval.string = NULL;
+			    sudoerslval.string = NULL;
 			    prev_state = YY_START;
 			    BEGIN INSTR;
 			}
 	YY_BREAK
 case 9:
 YY_RULE_SETUP
-#line 177 "toke.l"
+#line 178 "toke.l"
 {
 			    LEXTRACE("WORD(2) ");
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXRETURN(WORD);
 			}
@@ -1833,7 +1850,7 @@ YY_RULE_SETUP
 
 case 10:
 YY_RULE_SETUP
-#line 186 "toke.l"
+#line 187 "toke.l"
 {
 			    /* Line continuation char followed by newline. */
 			    sudolineno++;
@@ -1842,28 +1859,28 @@ YY_RULE_SETUP
 	YY_BREAK
 case 11:
 YY_RULE_SETUP
-#line 192 "toke.l"
+#line 193 "toke.l"
 {
 			    LEXTRACE("ENDSTR ");
 			    BEGIN prev_state;
 
-			    if (yylval.string == NULL) {
+			    if (sudoerslval.string == NULL) {
 				LEXTRACE("ERROR "); /* empty string */
 				LEXRETURN(ERROR);
 			    }
 			    if (prev_state == INITIAL) {
-				switch (yylval.string[0]) {
+				switch (sudoerslval.string[0]) {
 				case '%':
-				    if (yylval.string[1] == '\0' ||
-					(yylval.string[1] == ':' &&
-					yylval.string[2] == '\0')) {
+				    if (sudoerslval.string[1] == '\0' ||
+					(sudoerslval.string[1] == ':' &&
+					sudoerslval.string[2] == '\0')) {
 					LEXTRACE("ERROR "); /* empty group */
 					LEXRETURN(ERROR);
 				    }
 				    LEXTRACE("USERGROUP ");
 				    LEXRETURN(USERGROUP);
 				case '+':
-				    if (yylval.string[1] == '\0') {
+				    if (sudoerslval.string[1] == '\0') {
 					LEXTRACE("ERROR "); /* empty netgroup */
 					LEXRETURN(ERROR);
 				    }
@@ -1877,19 +1894,19 @@ YY_RULE_SETUP
 	YY_BREAK
 case 12:
 YY_RULE_SETUP
-#line 224 "toke.l"
+#line 225 "toke.l"
 {
 			    LEXTRACE("BACKSLASH ");
-			    if (!append(yytext, yyleng))
+			    if (!append(sudoerstext, sudoersleng))
 				yyterminate();
 			}
 	YY_BREAK
 case 13:
 YY_RULE_SETUP
-#line 230 "toke.l"
+#line 231 "toke.l"
 {
 			    LEXTRACE("STRBODY ");
-			    if (!append(yytext, yyleng))
+			    if (!append(sudoerstext, sudoersleng))
 				yyterminate();
 			}
 	YY_BREAK
@@ -1897,29 +1914,29 @@ YY_RULE_SETUP
 
 case 14:
 YY_RULE_SETUP
-#line 238 "toke.l"
+#line 239 "toke.l"
 {
 			    /* quoted fnmatch glob char, pass verbatim */
 			    LEXTRACE("QUOTEDCHAR ");
-			    if (!fill_args(yytext, 2, sawspace))
+			    if (!fill_args(sudoerstext, 2, sawspace))
 				yyterminate();
 			    sawspace = false;
 			}
 	YY_BREAK
 case 15:
 YY_RULE_SETUP
-#line 246 "toke.l"
+#line 247 "toke.l"
 {
 			    /* quoted sudoers special char, strip backslash */
 			    LEXTRACE("QUOTEDCHAR ");
-			    if (!fill_args(yytext + 1, 1, sawspace))
+			    if (!fill_args(sudoerstext + 1, 1, sawspace))
 				yyterminate();
 			    sawspace = false;
 			}
 	YY_BREAK
 case 16:
 YY_RULE_SETUP
-#line 254 "toke.l"
+#line 255 "toke.l"
 {
 			    BEGIN INITIAL;
 			    yyless(0);
@@ -1928,10 +1945,10 @@ YY_RULE_SETUP
 	YY_BREAK
 case 17:
 YY_RULE_SETUP
-#line 260 "toke.l"
+#line 261 "toke.l"
 {
 			    LEXTRACE("ARG ");
-			    if (!fill_args(yytext, yyleng, sawspace))
+			    if (!fill_args(sudoerstext, sudoersleng, sawspace))
 				yyterminate();
 			    sawspace = false;
 			}			/* a command line arg */
@@ -1939,7 +1956,7 @@ YY_RULE_SETUP
 
 case 18:
 YY_RULE_SETUP
-#line 268 "toke.l"
+#line 269 "toke.l"
 {
 			    char *path;
 
@@ -1948,7 +1965,7 @@ YY_RULE_SETUP
 				LEXRETURN(ERROR);
 			    }
 
-			    if ((path = parse_include(yytext)) == NULL)
+			    if ((path = parse_include(sudoerstext)) == NULL)
 				yyterminate();
 
 			    LEXTRACE("INCLUDE\n");
@@ -1960,7 +1977,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 19:
 YY_RULE_SETUP
-#line 286 "toke.l"
+#line 287 "toke.l"
 {
 			    char *path;
 
@@ -1969,7 +1986,7 @@ YY_RULE_SETUP
 				LEXRETURN(ERROR);
 			    }
 
-			    if ((path = parse_include(yytext)) == NULL)
+			    if ((path = parse_include(sudoerstext)) == NULL)
 				yyterminate();
 
 			    LEXTRACE("INCLUDEDIR\n");
@@ -1984,7 +2001,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 20:
 YY_RULE_SETUP
-#line 307 "toke.l"
+#line 308 "toke.l"
 {
 			    char deftype;
 			    int n;
@@ -1994,11 +2011,11 @@ YY_RULE_SETUP
 				LEXRETURN(ERROR);
 			    }
 
-			    for (n = 0; isblank((unsigned char)yytext[n]); n++)
+			    for (n = 0; isblank((unsigned char)sudoerstext[n]); n++)
 				continue;
 			    n += sizeof("Defaults") - 1;
-			    if ((deftype = yytext[n++]) != '\0') {
-				while (isblank((unsigned char)yytext[n]))
+			    if ((deftype = sudoerstext[n++]) != '\0') {
+				while (isblank((unsigned char)sudoerstext[n]))
 				    n++;
 			    }
 			    BEGIN GOTDEFS;
@@ -2027,7 +2044,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 21:
 YY_RULE_SETUP
-#line 347 "toke.l"
+#line 348 "toke.l"
 {
 			    int n;
 
@@ -2036,9 +2053,9 @@ YY_RULE_SETUP
 				LEXRETURN(ERROR);
 			    }
 
-			    for (n = 0; isblank((unsigned char)yytext[n]); n++)
+			    for (n = 0; isblank((unsigned char)sudoerstext[n]); n++)
 				continue;
-			    switch (yytext[n]) {
+			    switch (sudoerstext[n]) {
 				case 'H':
 				    LEXTRACE("HOSTALIAS ");
 				    LEXRETURN(HOSTALIAS);
@@ -2056,7 +2073,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 22:
 YY_RULE_SETUP
-#line 373 "toke.l"
+#line 374 "toke.l"
 {
 				/* cmnd does not require passwd for this user */
 			    	LEXTRACE("NOPASSWD ");
@@ -2065,7 +2082,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 23:
 YY_RULE_SETUP
-#line 379 "toke.l"
+#line 380 "toke.l"
 {
 				/* cmnd requires passwd for this user */
 			    	LEXTRACE("PASSWD ");
@@ -2074,7 +2091,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 24:
 YY_RULE_SETUP
-#line 385 "toke.l"
+#line 386 "toke.l"
 {
 			    	LEXTRACE("NOEXEC ");
 			    	LEXRETURN(NOEXEC);
@@ -2082,7 +2099,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 25:
 YY_RULE_SETUP
-#line 390 "toke.l"
+#line 391 "toke.l"
 {
 			    	LEXTRACE("EXEC ");
 			    	LEXRETURN(EXEC);
@@ -2090,7 +2107,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 26:
 YY_RULE_SETUP
-#line 395 "toke.l"
+#line 396 "toke.l"
 {
 			    	LEXTRACE("SETENV ");
 			    	LEXRETURN(SETENV);
@@ -2098,7 +2115,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 27:
 YY_RULE_SETUP
-#line 400 "toke.l"
+#line 401 "toke.l"
 {
 			    	LEXTRACE("NOSETENV ");
 			    	LEXRETURN(NOSETENV);
@@ -2106,7 +2123,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 28:
 YY_RULE_SETUP
-#line 405 "toke.l"
+#line 406 "toke.l"
 {
 			    	LEXTRACE("LOG_OUTPUT ");
 			    	LEXRETURN(LOG_OUTPUT);
@@ -2114,7 +2131,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 29:
 YY_RULE_SETUP
-#line 410 "toke.l"
+#line 411 "toke.l"
 {
 			    	LEXTRACE("NOLOG_OUTPUT ");
 			    	LEXRETURN(NOLOG_OUTPUT);
@@ -2122,7 +2139,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 30:
 YY_RULE_SETUP
-#line 415 "toke.l"
+#line 416 "toke.l"
 {
 			    	LEXTRACE("LOG_INPUT ");
 			    	LEXRETURN(LOG_INPUT);
@@ -2130,7 +2147,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 31:
 YY_RULE_SETUP
-#line 420 "toke.l"
+#line 421 "toke.l"
 {
 			    	LEXTRACE("NOLOG_INPUT ");
 			    	LEXRETURN(NOLOG_INPUT);
@@ -2138,7 +2155,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 32:
 YY_RULE_SETUP
-#line 425 "toke.l"
+#line 426 "toke.l"
 {
 			    /* empty group or netgroup */
 			    LEXTRACE("ERROR ");
@@ -2147,10 +2164,10 @@ YY_RULE_SETUP
 	YY_BREAK
 case 33:
 YY_RULE_SETUP
-#line 431 "toke.l"
+#line 432 "toke.l"
 {
 			    /* netgroup */
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NETGROUP ");
 			    LEXRETURN(NETGROUP);
@@ -2158,10 +2175,10 @@ YY_RULE_SETUP
 	YY_BREAK
 case 34:
 YY_RULE_SETUP
-#line 439 "toke.l"
+#line 440 "toke.l"
 {
 			    /* group */
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("USERGROUP ");
 			    LEXRETURN(USERGROUP);
@@ -2169,9 +2186,9 @@ YY_RULE_SETUP
 	YY_BREAK
 case 35:
 YY_RULE_SETUP
-#line 447 "toke.l"
+#line 448 "toke.l"
 {
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NTWKADDR ");
 			    LEXRETURN(NTWKADDR);
@@ -2179,9 +2196,9 @@ YY_RULE_SETUP
 	YY_BREAK
 case 36:
 YY_RULE_SETUP
-#line 454 "toke.l"
+#line 455 "toke.l"
 {
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NTWKADDR ");
 			    LEXRETURN(NTWKADDR);
@@ -2189,13 +2206,13 @@ YY_RULE_SETUP
 	YY_BREAK
 case 37:
 YY_RULE_SETUP
-#line 461 "toke.l"
+#line 462 "toke.l"
 {
-			    if (!ipv6_valid(yytext)) {
+			    if (!ipv6_valid(sudoerstext)) {
 				LEXTRACE("ERROR ");
 				LEXRETURN(ERROR);
 			    }
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NTWKADDR ");
 			    LEXRETURN(NTWKADDR);
@@ -2203,13 +2220,13 @@ YY_RULE_SETUP
 	YY_BREAK
 case 38:
 YY_RULE_SETUP
-#line 472 "toke.l"
+#line 473 "toke.l"
 {
-			    if (!ipv6_valid(yytext)) {
+			    if (!ipv6_valid(sudoerstext)) {
 				LEXTRACE("ERROR ");
 				LEXRETURN(ERROR);
 			    }
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NTWKADDR ");
 			    LEXRETURN(NTWKADDR);
@@ -2217,7 +2234,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 39:
 YY_RULE_SETUP
-#line 483 "toke.l"
+#line 484 "toke.l"
 {
 			    LEXTRACE("ALL ");
 			    LEXRETURN(ALL);
@@ -2226,7 +2243,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 40:
 YY_RULE_SETUP
-#line 489 "toke.l"
+#line 490 "toke.l"
 {
 #ifdef HAVE_SELINUX
 			    LEXTRACE("ROLE ");
@@ -2238,7 +2255,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 41:
 YY_RULE_SETUP
-#line 498 "toke.l"
+#line 499 "toke.l"
 {
 #ifdef HAVE_SELINUX
 			    LEXTRACE("TYPE ");
@@ -2250,7 +2267,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 42:
 YY_RULE_SETUP
-#line 506 "toke.l"
+#line 507 "toke.l"
 {
 #ifdef HAVE_PRIV_SET
 			    LEXTRACE("PRIVS ");
@@ -2262,7 +2279,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 43:
 YY_RULE_SETUP
-#line 515 "toke.l"
+#line 516 "toke.l"
 {
 #ifdef HAVE_PRIV_SET
 			    LEXTRACE("LIMITPRIVS ");
@@ -2274,10 +2291,10 @@ YY_RULE_SETUP
 	YY_BREAK
 case 44:
 YY_RULE_SETUP
-#line 524 "toke.l"
+#line 525 "toke.l"
 {
 			got_alias:
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("ALIAS ");
 			    LEXRETURN(ALIAS);
@@ -2285,10 +2302,10 @@ YY_RULE_SETUP
 	YY_BREAK
 case 45:
 YY_RULE_SETUP
-#line 532 "toke.l"
+#line 533 "toke.l"
 {
 			    /* no command args allowed for Defaults!/path */
-			    if (!fill_cmnd(yytext, yyleng))
+			    if (!fill_cmnd(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("COMMAND ");
 			    LEXRETURN(COMMAND);
@@ -2296,48 +2313,48 @@ YY_RULE_SETUP
 	YY_BREAK
 case 46:
 YY_RULE_SETUP
-#line 540 "toke.l"
+#line 541 "toke.l"
 {
 			    BEGIN GOTCMND;
 			    LEXTRACE("COMMAND ");
-			    if (!fill_cmnd(yytext, yyleng))
+			    if (!fill_cmnd(sudoerstext, sudoersleng))
 				yyterminate();
 			}			/* sudo -e */
 	YY_BREAK
 case 47:
 YY_RULE_SETUP
-#line 547 "toke.l"
+#line 548 "toke.l"
 {
 			    /* directories can't have args... */
-			    if (yytext[yyleng - 1] == '/') {
+			    if (sudoerstext[sudoersleng - 1] == '/') {
 				LEXTRACE("COMMAND ");
-				if (!fill_cmnd(yytext, yyleng))
+				if (!fill_cmnd(sudoerstext, sudoersleng))
 				    yyterminate();
 				LEXRETURN(COMMAND);
 			    } else {
 				BEGIN GOTCMND;
 				LEXTRACE("COMMAND ");
-				if (!fill_cmnd(yytext, yyleng))
+				if (!fill_cmnd(sudoerstext, sudoersleng))
 				    yyterminate();
 			    }
 			}			/* a pathname */
 	YY_BREAK
 case 48:
 YY_RULE_SETUP
-#line 562 "toke.l"
+#line 563 "toke.l"
 {
 			    LEXTRACE("BEGINSTR ");
-			    yylval.string = NULL;
+			    sudoerslval.string = NULL;
 			    prev_state = YY_START;
 			    BEGIN INSTR;
 			}
 	YY_BREAK
 case 49:
 YY_RULE_SETUP
-#line 569 "toke.l"
+#line 570 "toke.l"
 {
 			    /* a word */
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("WORD(5) ");
 			    LEXRETURN(WORD);
@@ -2345,7 +2362,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 50:
 YY_RULE_SETUP
-#line 577 "toke.l"
+#line 578 "toke.l"
 {
 			    LEXTRACE("( ");
 			    LEXRETURN('(');
@@ -2353,7 +2370,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 51:
 YY_RULE_SETUP
-#line 582 "toke.l"
+#line 583 "toke.l"
 {
 			    LEXTRACE(") ");
 			    LEXRETURN(')');
@@ -2361,7 +2378,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 52:
 YY_RULE_SETUP
-#line 587 "toke.l"
+#line 588 "toke.l"
 {
 			    LEXTRACE(", ");
 			    LEXRETURN(',');
@@ -2369,7 +2386,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 53:
 YY_RULE_SETUP
-#line 592 "toke.l"
+#line 593 "toke.l"
 {
 			    LEXTRACE("= ");
 			    LEXRETURN('=');
@@ -2377,7 +2394,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 54:
 YY_RULE_SETUP
-#line 597 "toke.l"
+#line 598 "toke.l"
 {
 			    LEXTRACE(": ");
 			    LEXRETURN(':');
@@ -2385,9 +2402,9 @@ YY_RULE_SETUP
 	YY_BREAK
 case 55:
 YY_RULE_SETUP
-#line 602 "toke.l"
+#line 603 "toke.l"
 {
-			    if (yyleng & 1) {
+			    if (sudoersleng & 1) {
 				LEXTRACE("!");
 				LEXRETURN('!');	/* return '!' */
 			    }
@@ -2395,7 +2412,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 56:
 YY_RULE_SETUP
-#line 609 "toke.l"
+#line 610 "toke.l"
 {
 			    if (YY_START == INSTR) {
 				LEXTRACE("ERROR ");
@@ -2410,14 +2427,14 @@ YY_RULE_SETUP
 	YY_BREAK
 case 57:
 YY_RULE_SETUP
-#line 621 "toke.l"
+#line 622 "toke.l"
 {			/* throw away space/tabs */
 			    sawspace = true;	/* but remember for fill_args */
 			}
 	YY_BREAK
 case 58:
 YY_RULE_SETUP
-#line 625 "toke.l"
+#line 626 "toke.l"
 {
 			    sawspace = true;	/* remember for fill_args */
 			    sudolineno++;
@@ -2426,7 +2443,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 59:
 YY_RULE_SETUP
-#line 631 "toke.l"
+#line 632 "toke.l"
 {
 			    BEGIN INITIAL;
 			    sudolineno++;
@@ -2437,7 +2454,7 @@ YY_RULE_SETUP
 	YY_BREAK
 case 60:
 YY_RULE_SETUP
-#line 639 "toke.l"
+#line 640 "toke.l"
 {
 			    LEXTRACE("ERROR ");
 			    LEXRETURN(ERROR);
@@ -2449,7 +2466,7 @@ case YY_STATE_EOF(GOTCMND):
 case YY_STATE_EOF(STARTDEFS):
 case YY_STATE_EOF(INDEFS):
 case YY_STATE_EOF(INSTR):
-#line 644 "toke.l"
+#line 645 "toke.l"
 {
 			    if (YY_START != INITIAL) {
 			    	BEGIN INITIAL;
@@ -2462,10 +2479,10 @@ case YY_STATE_EOF(INSTR):
 	YY_BREAK
 case 61:
 YY_RULE_SETUP
-#line 654 "toke.l"
+#line 655 "toke.l"
 ECHO;
 	YY_BREAK
-#line 2468 "lex.yy.c"
+#line 2485 "lex.sudoers.c"
 
 	case YY_END_OF_BUFFER:
 		{
@@ -3356,7 +3373,7 @@ int main()
 	return 0;
 	}
 #endif
-#line 654 "toke.l"
+#line 655 "toke.l"
 
 struct path_list {
     char *path;
@@ -3396,10 +3413,10 @@ switch_dir(struct include_stack *stack, char *dirpath)
 	if (errno != ENOENT) {
 	    char *errbuf;
 	    if (asprintf(&errbuf, _("%s: %s"), dirpath, strerror(errno)) != -1) {
-		yyerror(errbuf);
+		sudoerserror(errbuf);
 		free(errbuf);
 	    } else {
-		yyerror(_("unable to allocate memory"));
+		sudoerserror(_("unable to allocate memory"));
 	    }
 	}
 	goto done;
@@ -3498,7 +3515,7 @@ init_lexer(void)
 	efree(istack[idepth].path);
 	if (idepth && !istack[idepth].keepopen)
 	    fclose(istack[idepth].bs->yy_input_file);
-	yy_delete_buffer(istack[idepth].bs);
+	sudoers_delete_buffer(istack[idepth].bs);
     }
     efree(istack);
     istack = NULL;
@@ -3522,14 +3539,14 @@ _push_include(char *path, bool isdir)
     /* push current state onto stack */
     if (idepth >= istacksize) {
 	if (idepth > MAX_SUDOERS_DEPTH) {
-	    yyerror(_("too many levels of includes"));
+	    sudoerserror(_("too many levels of includes"));
 	    debug_return_bool(false);
 	}
 	istacksize += SUDOERS_STACK_INCREMENT;
 	istack = (struct include_stack *) realloc(istack,
 	    sizeof(*istack) * istacksize);
 	if (istack == NULL) {
-	    yyerror(_("unable to allocate memory"));
+	    sudoerserror(_("unable to allocate memory"));
 	    debug_return_bool(false);
 	}
     }
@@ -3570,7 +3587,7 @@ _push_include(char *path, bool isdir)
 		debug_return_bool(false);
 	}
 	if (!(path = switch_dir(&istack[idepth], path))) {
-	    /* switch_dir() called yyerror() for us */
+	    /* switch_dir() called sudoerserror() for us */
 	    debug_return_bool(false);
 	}
 	while ((fp = open_sudoers(path, false, &keepopen)) == NULL) {
@@ -3585,7 +3602,7 @@ _push_include(char *path, bool isdir)
     } else {
 	if ((fp = open_sudoers(path, true, &keepopen)) == NULL) {
 	    /* The error was already printed by open_sudoers() */
-	    yyerror(NULL);
+	    sudoerserror(NULL);
 	    debug_return_bool(false);
 	}
 	istack[idepth].more = NULL;
@@ -3598,7 +3615,7 @@ _push_include(char *path, bool isdir)
     idepth++;
     sudolineno = 1;
     sudoers = path;
-    yy_switch_to_buffer(yy_create_buffer(fp, YY_BUF_SIZE));
+    sudoers_switch_to_buffer(sudoers_create_buffer(fp, YY_BUF_SIZE));
 
     debug_return_bool(true);
 }
@@ -3615,7 +3632,7 @@ pop_include(void)
 
     if (!keepopen)
 	fclose(YY_CURRENT_BUFFER->yy_input_file);
-    yy_delete_buffer(YY_CURRENT_BUFFER);
+    sudoers_delete_buffer(YY_CURRENT_BUFFER);
     /* If we are in an include dir, move to the next file. */
     while ((pl = istack[idepth - 1].more) != NULL) {
 	fp = open_sudoers(pl->path, false, &keepopen);
@@ -3624,7 +3641,7 @@ pop_include(void)
 	    efree(sudoers);
 	    sudoers = pl->path;
 	    sudolineno = 1;
-	    yy_switch_to_buffer(yy_create_buffer(fp, YY_BUF_SIZE));
+	    sudoers_switch_to_buffer(sudoers_create_buffer(fp, YY_BUF_SIZE));
 	    efree(pl);
 	    break;
 	}
@@ -3636,7 +3653,7 @@ pop_include(void)
     /* If no path list, just pop the last dir on the stack. */
     if (pl == NULL) {
 	idepth--;
-	yy_switch_to_buffer(istack[idepth].bs);
+	sudoers_switch_to_buffer(istack[idepth].bs);
 	efree(sudoers);
 	sudoers = istack[idepth].path;
 	sudolineno = istack[idepth].lineno;
@@ -3680,7 +3697,7 @@ parse_include(char *base)
     len += (int)(ep - cp);
     path = pp = malloc(len + dirlen + 1);
     if (path == NULL) {
-	yyerror(_("unable to allocate memory"));
+	sudoerserror(_("unable to allocate memory"));
 	debug_return_str(NULL);
     }
     if (dirlen) {
diff --git a/plugins/sudoers/toke.h b/plugins/sudoers/toke.h
index c0ab53fe1..513dd8fb3 100644
--- a/plugins/sudoers/toke.h
+++ b/plugins/sudoers/toke.h
@@ -23,7 +23,7 @@ bool fill_cmnd(const char *, int);
 bool fill_txt(const char *, int, int);
 bool ipv6_valid(const char *s);
 int sudoers_trace_print(const char *msg);
-void yyerror(const char *);
+void sudoerserror(const char *);
 
 #ifndef FLEX_SCANNER
 extern int (*trace_print)(const char *msg);
diff --git a/plugins/sudoers/toke.l b/plugins/sudoers/toke.l
index 9d51364be..cf4fa8e7d 100644
--- a/plugins/sudoers/toke.l
+++ b/plugins/sudoers/toke.l
@@ -74,7 +74,7 @@
 #include "lbuf.h"
 #include "secure_path.h"
 
-extern YYSTYPE yylval;
+extern YYSTYPE sudoerslval;
 extern bool parse_error;
 extern bool sudoers_warnings;
 int sudolineno;
@@ -101,7 +101,7 @@ int (*trace_print)(const char *msg) = sudoers_trace_print;
 	return (n);		\
 } while (0)
 
-#define ECHO	ignore_result(fwrite(yytext, yyleng, 1, yyout))
+#define ECHO	ignore_result(fwrite(sudoerstext, sudoersleng, 1, sudoersout))
 
 #define	push_include(_p)	(_push_include((_p), false))
 #define	push_includedir(_p)	(_push_include((_p), true))
@@ -122,6 +122,7 @@ DEFVAR			[a-z_]+
 %option noinput
 %option nounput
 %option noyywrap
+%option prefix="sudoers"
 
 %s	GOTDEFS
 %x	GOTCMND
@@ -140,7 +141,7 @@ DEFVAR			[a-z_]+
 <STARTDEFS>{DEFVAR}	{
 			    BEGIN INDEFS;
 			    LEXTRACE("DEFVAR ");
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXRETURN(DEFVAR);
 			}
@@ -169,14 +170,14 @@ DEFVAR			[a-z_]+
 
     \"			{
 			    LEXTRACE("BEGINSTR ");
-			    yylval.string = NULL;
+			    sudoerslval.string = NULL;
 			    prev_state = YY_START;
 			    BEGIN INSTR;
 			}
 
     {ENVAR}		{
 			    LEXTRACE("WORD(2) ");
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXRETURN(WORD);
 			}
@@ -193,23 +194,23 @@ DEFVAR			[a-z_]+
 			    LEXTRACE("ENDSTR ");
 			    BEGIN prev_state;
 
-			    if (yylval.string == NULL) {
+			    if (sudoerslval.string == NULL) {
 				LEXTRACE("ERROR "); /* empty string */
 				LEXRETURN(ERROR);
 			    }
 			    if (prev_state == INITIAL) {
-				switch (yylval.string[0]) {
+				switch (sudoerslval.string[0]) {
 				case '%':
-				    if (yylval.string[1] == '\0' ||
-					(yylval.string[1] == ':' &&
-					yylval.string[2] == '\0')) {
+				    if (sudoerslval.string[1] == '\0' ||
+					(sudoerslval.string[1] == ':' &&
+					sudoerslval.string[2] == '\0')) {
 					LEXTRACE("ERROR "); /* empty group */
 					LEXRETURN(ERROR);
 				    }
 				    LEXTRACE("USERGROUP ");
 				    LEXRETURN(USERGROUP);
 				case '+':
-				    if (yylval.string[1] == '\0') {
+				    if (sudoerslval.string[1] == '\0') {
 					LEXTRACE("ERROR "); /* empty netgroup */
 					LEXRETURN(ERROR);
 				    }
@@ -223,13 +224,13 @@ DEFVAR			[a-z_]+
 
     \\			{
 			    LEXTRACE("BACKSLASH ");
-			    if (!append(yytext, yyleng))
+			    if (!append(sudoerstext, sudoersleng))
 				yyterminate();
 			}
 
     ([^\"\n\\]|\\\")+	{
 			    LEXTRACE("STRBODY ");
-			    if (!append(yytext, yyleng))
+			    if (!append(sudoerstext, sudoersleng))
 				yyterminate();
 			}
 }
@@ -238,7 +239,7 @@ DEFVAR			[a-z_]+
     \\[\*\?\[\]\!]	{
 			    /* quoted fnmatch glob char, pass verbatim */
 			    LEXTRACE("QUOTEDCHAR ");
-			    if (!fill_args(yytext, 2, sawspace))
+			    if (!fill_args(sudoerstext, 2, sawspace))
 				yyterminate();
 			    sawspace = false;
 			}
@@ -246,7 +247,7 @@ DEFVAR			[a-z_]+
     \\[:\\,= \t#]	{
 			    /* quoted sudoers special char, strip backslash */
 			    LEXTRACE("QUOTEDCHAR ");
-			    if (!fill_args(yytext + 1, 1, sawspace))
+			    if (!fill_args(sudoerstext + 1, 1, sawspace))
 				yyterminate();
 			    sawspace = false;
 			}
@@ -259,7 +260,7 @@ DEFVAR			[a-z_]+
 
     [^#\\:, \t\n]+ 	{
 			    LEXTRACE("ARG ");
-			    if (!fill_args(yytext, yyleng, sawspace))
+			    if (!fill_args(sudoerstext, sudoersleng, sawspace))
 				yyterminate();
 			    sawspace = false;
 			}			/* a command line arg */
@@ -273,7 +274,7 @@ DEFVAR			[a-z_]+
 				LEXRETURN(ERROR);
 			    }
 
-			    if ((path = parse_include(yytext)) == NULL)
+			    if ((path = parse_include(sudoerstext)) == NULL)
 				yyterminate();
 
 			    LEXTRACE("INCLUDE\n");
@@ -291,7 +292,7 @@ DEFVAR			[a-z_]+
 				LEXRETURN(ERROR);
 			    }
 
-			    if ((path = parse_include(yytext)) == NULL)
+			    if ((path = parse_include(sudoerstext)) == NULL)
 				yyterminate();
 
 			    LEXTRACE("INCLUDEDIR\n");
@@ -313,11 +314,11 @@ DEFVAR			[a-z_]+
 				LEXRETURN(ERROR);
 			    }
 
-			    for (n = 0; isblank((unsigned char)yytext[n]); n++)
+			    for (n = 0; isblank((unsigned char)sudoerstext[n]); n++)
 				continue;
 			    n += sizeof("Defaults") - 1;
-			    if ((deftype = yytext[n++]) != '\0') {
-				while (isblank((unsigned char)yytext[n]))
+			    if ((deftype = sudoerstext[n++]) != '\0') {
+				while (isblank((unsigned char)sudoerstext[n]))
 				    n++;
 			    }
 			    BEGIN GOTDEFS;
@@ -352,9 +353,9 @@ DEFVAR			[a-z_]+
 				LEXRETURN(ERROR);
 			    }
 
-			    for (n = 0; isblank((unsigned char)yytext[n]); n++)
+			    for (n = 0; isblank((unsigned char)sudoerstext[n]); n++)
 				continue;
-			    switch (yytext[n]) {
+			    switch (sudoerstext[n]) {
 				case 'H':
 				    LEXTRACE("HOSTALIAS ");
 				    LEXRETURN(HOSTALIAS);
@@ -430,7 +431,7 @@ NOLOG_INPUT[[:blank:]]*:	{
 
 \+{WORD}		{
 			    /* netgroup */
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NETGROUP ");
 			    LEXRETURN(NETGROUP);
@@ -438,43 +439,43 @@ NOLOG_INPUT[[:blank:]]*:	{
 
 \%:?({WORD}|{ID})	{
 			    /* group */
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("USERGROUP ");
 			    LEXRETURN(USERGROUP);
 			}
 
 {IPV4ADDR}(\/{IPV4ADDR})? {
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NTWKADDR ");
 			    LEXRETURN(NTWKADDR);
 			}
 
 {IPV4ADDR}\/([12]?[0-9]|3[0-2]) {
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NTWKADDR ");
 			    LEXRETURN(NTWKADDR);
 			}
 
 {IPV6ADDR}(\/{IPV6ADDR})? {
-			    if (!ipv6_valid(yytext)) {
+			    if (!ipv6_valid(sudoerstext)) {
 				LEXTRACE("ERROR ");
 				LEXRETURN(ERROR);
 			    }
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NTWKADDR ");
 			    LEXRETURN(NTWKADDR);
 			}
 
 {IPV6ADDR}\/([0-9]|[1-9][0-9]|1[01][0-9]|12[0-8]) {
-			    if (!ipv6_valid(yytext)) {
+			    if (!ipv6_valid(sudoerstext)) {
 				LEXTRACE("ERROR ");
 				LEXRETURN(ERROR);
 			    }
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("NTWKADDR ");
 			    LEXRETURN(NTWKADDR);
@@ -523,7 +524,7 @@ ALL {
 
 [[:upper:]][[:upper:][:digit:]_]* {
 			got_alias:
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("ALIAS ");
 			    LEXRETURN(ALIAS);
@@ -531,7 +532,7 @@ ALL {
 
 <GOTDEFS>({PATH}|sudoedit) {
 			    /* no command args allowed for Defaults!/path */
-			    if (!fill_cmnd(yytext, yyleng))
+			    if (!fill_cmnd(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("COMMAND ");
 			    LEXRETURN(COMMAND);
@@ -540,35 +541,35 @@ ALL {
 sudoedit		{
 			    BEGIN GOTCMND;
 			    LEXTRACE("COMMAND ");
-			    if (!fill_cmnd(yytext, yyleng))
+			    if (!fill_cmnd(sudoerstext, sudoersleng))
 				yyterminate();
 			}			/* sudo -e */
 
 {PATH}			{
 			    /* directories can't have args... */
-			    if (yytext[yyleng - 1] == '/') {
+			    if (sudoerstext[sudoersleng - 1] == '/') {
 				LEXTRACE("COMMAND ");
-				if (!fill_cmnd(yytext, yyleng))
+				if (!fill_cmnd(sudoerstext, sudoersleng))
 				    yyterminate();
 				LEXRETURN(COMMAND);
 			    } else {
 				BEGIN GOTCMND;
 				LEXTRACE("COMMAND ");
-				if (!fill_cmnd(yytext, yyleng))
+				if (!fill_cmnd(sudoerstext, sudoersleng))
 				    yyterminate();
 			    }
 			}			/* a pathname */
 
 <INITIAL,GOTDEFS>\" {
 			    LEXTRACE("BEGINSTR ");
-			    yylval.string = NULL;
+			    sudoerslval.string = NULL;
 			    prev_state = YY_START;
 			    BEGIN INSTR;
 			}
 
 <INITIAL,GOTDEFS>({ID}|{WORD}) {
 			    /* a word */
-			    if (!fill(yytext, yyleng))
+			    if (!fill(sudoerstext, sudoersleng))
 				yyterminate();
 			    LEXTRACE("WORD(5) ");
 			    LEXRETURN(WORD);
@@ -600,7 +601,7 @@ sudoedit		{
 			}			/* return ':' */
 
 <*>!+			{
-			    if (yyleng & 1) {
+			    if (sudoersleng & 1) {
 				LEXTRACE("!");
 				LEXRETURN('!');	/* return '!' */
 			    }
@@ -690,10 +691,10 @@ switch_dir(struct include_stack *stack, char *dirpath)
 	if (errno != ENOENT) {
 	    char *errbuf;
 	    if (asprintf(&errbuf, _("%s: %s"), dirpath, strerror(errno)) != -1) {
-		yyerror(errbuf);
+		sudoerserror(errbuf);
 		free(errbuf);
 	    } else {
-		yyerror(_("unable to allocate memory"));
+		sudoerserror(_("unable to allocate memory"));
 	    }
 	}
 	goto done;
@@ -792,7 +793,7 @@ init_lexer(void)
 	efree(istack[idepth].path);
 	if (idepth && !istack[idepth].keepopen)
 	    fclose(istack[idepth].bs->yy_input_file);
-	yy_delete_buffer(istack[idepth].bs);
+	sudoers_delete_buffer(istack[idepth].bs);
     }
     efree(istack);
     istack = NULL;
@@ -816,14 +817,14 @@ _push_include(char *path, bool isdir)
     /* push current state onto stack */
     if (idepth >= istacksize) {
 	if (idepth > MAX_SUDOERS_DEPTH) {
-	    yyerror(_("too many levels of includes"));
+	    sudoerserror(_("too many levels of includes"));
 	    debug_return_bool(false);
 	}
 	istacksize += SUDOERS_STACK_INCREMENT;
 	istack = (struct include_stack *) realloc(istack,
 	    sizeof(*istack) * istacksize);
 	if (istack == NULL) {
-	    yyerror(_("unable to allocate memory"));
+	    sudoerserror(_("unable to allocate memory"));
 	    debug_return_bool(false);
 	}
     }
@@ -864,7 +865,7 @@ _push_include(char *path, bool isdir)
 		debug_return_bool(false);
 	}
 	if (!(path = switch_dir(&istack[idepth], path))) {
-	    /* switch_dir() called yyerror() for us */
+	    /* switch_dir() called sudoerserror() for us */
 	    debug_return_bool(false);
 	}
 	while ((fp = open_sudoers(path, false, &keepopen)) == NULL) {
@@ -879,7 +880,7 @@ _push_include(char *path, bool isdir)
     } else {
 	if ((fp = open_sudoers(path, true, &keepopen)) == NULL) {
 	    /* The error was already printed by open_sudoers() */
-	    yyerror(NULL);
+	    sudoerserror(NULL);
 	    debug_return_bool(false);
 	}
 	istack[idepth].more = NULL;
@@ -892,7 +893,7 @@ _push_include(char *path, bool isdir)
     idepth++;
     sudolineno = 1;
     sudoers = path;
-    yy_switch_to_buffer(yy_create_buffer(fp, YY_BUF_SIZE));
+    sudoers_switch_to_buffer(sudoers_create_buffer(fp, YY_BUF_SIZE));
 
     debug_return_bool(true);
 }
@@ -909,7 +910,7 @@ pop_include(void)
 
     if (!keepopen)
 	fclose(YY_CURRENT_BUFFER->yy_input_file);
-    yy_delete_buffer(YY_CURRENT_BUFFER);
+    sudoers_delete_buffer(YY_CURRENT_BUFFER);
     /* If we are in an include dir, move to the next file. */
     while ((pl = istack[idepth - 1].more) != NULL) {
 	fp = open_sudoers(pl->path, false, &keepopen);
@@ -918,7 +919,7 @@ pop_include(void)
 	    efree(sudoers);
 	    sudoers = pl->path;
 	    sudolineno = 1;
-	    yy_switch_to_buffer(yy_create_buffer(fp, YY_BUF_SIZE));
+	    sudoers_switch_to_buffer(sudoers_create_buffer(fp, YY_BUF_SIZE));
 	    efree(pl);
 	    break;
 	}
@@ -930,7 +931,7 @@ pop_include(void)
     /* If no path list, just pop the last dir on the stack. */
     if (pl == NULL) {
 	idepth--;
-	yy_switch_to_buffer(istack[idepth].bs);
+	sudoers_switch_to_buffer(istack[idepth].bs);
 	efree(sudoers);
 	sudoers = istack[idepth].path;
 	sudolineno = istack[idepth].lineno;
@@ -974,7 +975,7 @@ parse_include(char *base)
     len += (int)(ep - cp);
     path = pp = malloc(len + dirlen + 1);
     if (path == NULL) {
-	yyerror(_("unable to allocate memory"));
+	sudoerserror(_("unable to allocate memory"));
 	debug_return_str(NULL);
     }
     if (dirlen) {
diff --git a/plugins/sudoers/toke_util.c b/plugins/sudoers/toke_util.c
index 330279452..8c18cfed0 100644
--- a/plugins/sudoers/toke_util.c
+++ b/plugins/sudoers/toke_util.c
@@ -108,12 +108,12 @@ fill_txt(const char *src, int len, int olen)
     char *dst;
     debug_decl(fill_txt, SUDO_DEBUG_PARSER)
 
-    dst = olen ? realloc(yylval.string, olen + len + 1) : malloc(len + 1);
+    dst = olen ? realloc(sudoerslval.string, olen + len + 1) : malloc(len + 1);
     if (dst == NULL) {
-	yyerror(_("unable to allocate memory"));
+	sudoerserror(_("unable to allocate memory"));
 	debug_return_bool(false);
     }
-    yylval.string = dst;
+    sudoerslval.string = dst;
 
     /* Copy the string and collapse any escaped characters. */
     dst += olen;
@@ -144,8 +144,8 @@ append(const char *src, int len)
     int olen = 0;
     debug_decl(append, SUDO_DEBUG_PARSER)
 
-    if (yylval.string != NULL)
-	olen = strlen(yylval.string);
+    if (sudoerslval.string != NULL)
+	olen = strlen(sudoerslval.string);
 
     debug_return_bool(fill_txt(src, len, olen));
 }
@@ -162,9 +162,9 @@ fill_cmnd(const char *src, int len)
 
     arg_len = arg_size = 0;
 
-    dst = yylval.command.cmnd = (char *) malloc(len + 1);
-    if (yylval.command.cmnd == NULL) {
-	yyerror(_("unable to allocate memory"));
+    dst = sudoerslval.command.cmnd = (char *) malloc(len + 1);
+    if (sudoerslval.command.cmnd == NULL) {
+	sudoerserror(_("unable to allocate memory"));
 	debug_return_bool(false);
     }
 
@@ -177,7 +177,7 @@ fill_cmnd(const char *src, int len)
     }
     *dst = '\0';
 
-    yylval.command.args = NULL;
+    sudoerslval.command.args = NULL;
     debug_return_bool(true);
 }
 
@@ -188,7 +188,7 @@ fill_args(const char *s, int len, int addspace)
     char *p;
     debug_decl(fill_args, SUDO_DEBUG_PARSER)
 
-    if (yylval.command.args == NULL) {
+    if (sudoerslval.command.args == NULL) {
 	addspace = 0;
 	new_len = len;
     } else
@@ -199,23 +199,23 @@ fill_args(const char *s, int len, int addspace)
 	while (new_len >= (arg_size += COMMANDARGINC))
 	    ;
 
-	p = yylval.command.args ?
-	    (char *) realloc(yylval.command.args, arg_size) :
+	p = sudoerslval.command.args ?
+	    (char *) realloc(sudoerslval.command.args, arg_size) :
 	    (char *) malloc(arg_size);
 	if (p == NULL) {
-	    efree(yylval.command.args);
-	    yyerror(_("unable to allocate memory"));
+	    efree(sudoerslval.command.args);
+	    sudoerserror(_("unable to allocate memory"));
 	    debug_return_bool(false);
 	} else
-	    yylval.command.args = p;
+	    sudoerslval.command.args = p;
     }
 
     /* Efficiently append the arg (with a leading space if needed). */
-    p = yylval.command.args + arg_len;
+    p = sudoerslval.command.args + arg_len;
     if (addspace)
 	*p++ = ' ';
-    if (strlcpy(p, s, arg_size - (p - yylval.command.args)) != len) {
-	yyerror(_("fill_args: buffer overflow"));	/* paranoia */
+    if (strlcpy(p, s, arg_size - (p - sudoerslval.command.args)) != len) {
+	sudoerserror(_("fill_args: buffer overflow"));	/* paranoia */
 	debug_return_bool(false);
     }
     arg_len = new_len;
diff --git a/plugins/sudoers/visudo.c b/plugins/sudoers/visudo.c
index 55c57fdd5..d8248ee45 100644
--- a/plugins/sudoers/visudo.c
+++ b/plugins/sudoers/visudo.c
@@ -118,14 +118,14 @@ static void usage(int);
 
 void cleanup(int);
 
-extern void yyerror(const char *);
-extern void yyrestart(FILE *);
+extern void sudoerserror(const char *);
+extern void sudoersrestart(FILE *);
 
 /*
  * External globals exported by the parser
  */
 extern struct rbtree *aliases;
-extern FILE *yyin;
+extern FILE *sudoersin;
 extern char *sudoers, *errorfile;
 extern int errorlineno;
 extern bool parse_error;
@@ -232,11 +232,11 @@ main(int argc, char *argv[])
      * Parse the existing sudoers file(s) in quiet mode to highlight any
      * existing errors and to pull in editor and env_editor conf values.
      */
-    if ((yyin = open_sudoers(sudoers_path, true, NULL)) == NULL) {
+    if ((sudoersin = open_sudoers(sudoers_path, true, NULL)) == NULL) {
 	error(1, "%s", sudoers_path);
     }
     init_parser(sudoers_path, false);
-    yyparse();
+    sudoersparse();
     (void) update_defaults(SETDEF_GENERIC|SETDEF_HOST|SETDEF_USER);
 
     editor = get_editor(&args);
@@ -491,14 +491,14 @@ reparse_sudoers(char *editor, char *args, bool strict, bool quiet)
 	init_parser(sp->path, quiet);
 
 	/* Parse the sudoers temp file */
-	yyrestart(fp);
-	if (yyparse() && !parse_error) {
+	sudoersrestart(fp);
+	if (sudoersparse() && !parse_error) {
 	    warningx(_("unabled to parse temporary file (%s), unknown error"),
 		sp->tpath);
 	    parse_error = true;
 	    errorfile = sp->path;
 	}
-	fclose(yyin);
+	fclose(sudoersin);
 	if (!parse_error) {
 	    if (!check_defaults(SETDEF_ALL, quiet) ||
 		check_aliases(strict, quiet) != 0) {
@@ -812,15 +812,15 @@ check_syntax(char *sudoers_path, bool quiet, bool strict, bool oldperms)
     debug_decl(check_syntax, SUDO_DEBUG_UTIL)
 
     if (strcmp(sudoers_path, "-") == 0) {
-	yyin = stdin;
+	sudoersin = stdin;
 	sudoers_path = "stdin";
-    } else if ((yyin = fopen(sudoers_path, "r")) == NULL) {
+    } else if ((sudoersin = fopen(sudoers_path, "r")) == NULL) {
 	if (!quiet)
 	    warning(_("unable to open %s"), sudoers_path);
 	goto done;
     }
     init_parser(sudoers_path, quiet);
-    if (yyparse() && !parse_error) {
+    if (sudoersparse() && !parse_error) {
 	if (!quiet)
 	    warningx(_("failed to parse %s file, unknown error"), sudoers_path);
 	parse_error = true;