diff --git a/MANIFEST b/MANIFEST
index 244ae236d..da3bbd67d 100644
--- a/MANIFEST
+++ b/MANIFEST
@@ -161,7 +161,6 @@ lib/util/strtonum.c
 lib/util/sudo_conf.c
 lib/util/sudo_debug.c
 lib/util/sudo_dso.c
-lib/util/sudo_printf.c
 lib/util/term.c
 lib/util/ttysize.c
 lib/util/util.exp.in
@@ -429,6 +428,7 @@ plugins/sudoers/solaris_audit.h
 plugins/sudoers/sssd.c
 plugins/sudoers/sudo_nss.c
 plugins/sudoers/sudo_nss.h
+plugins/sudoers/sudo_printf.c
 plugins/sudoers/sudoers.c
 plugins/sudoers/sudoers.exp
 plugins/sudoers/sudoers.h
diff --git a/include/sudo_fatal.h b/include/sudo_fatal.h
index 37dafb075..9c1c7833d 100644
--- a/include/sudo_fatal.h
+++ b/include/sudo_fatal.h
@@ -114,6 +114,9 @@
 
 typedef void (*sudo_fatal_callback_t)(void);
 
+struct sudo_conv_message;
+struct sudo_conv_reply;
+
 __dso_public int  sudo_fatal_callback_deregister_v1(sudo_fatal_callback_t func);
 __dso_public int  sudo_fatal_callback_register_v1(sudo_fatal_callback_t func);
 __dso_public char *sudo_warn_gettext_v1(const char *msgid) __format_arg(1);
@@ -126,6 +129,7 @@ __dso_public void sudo_warn_nodebug_v1(const char *fmt, ...) __printf0like(1, 2)
 __dso_public void sudo_warnx_nodebug_v1(const char *fmt, ...) __printflike(1, 2);
 __dso_public void sudo_vwarn_nodebug_v1(const char *fmt, va_list ap) __printf0like(1, 0);
 __dso_public void sudo_vwarnx_nodebug_v1(const char *fmt, va_list ap) __printflike(1, 0);
+__dso_public void sudo_warn_set_conversation_v1(int (*conv)(int num_msgs, const struct sudo_conv_message *msgs, struct sudo_conv_reply *replies));
 
 #define sudo_fatal_callback_deregister(_a) sudo_fatal_callback_deregister_v1((_a))
 #define sudo_fatal_callback_register(_a) sudo_fatal_callback_register_v1((_a))
@@ -139,5 +143,6 @@ __dso_public void sudo_vwarnx_nodebug_v1(const char *fmt, va_list ap) __printfli
 #define sudo_warnx_nodebug sudo_warnx_nodebug_v1
 #define sudo_vwarn_nodebug(_a, _b) sudo_vwarn_nodebug_v1((_a), (_b))
 #define sudo_vwarnx_nodebug(_a, _b) sudo_vwarnx_nodebug_v1((_a), (_b))
+#define sudo_warn_set_conversation(_a) sudo_warn_set_conversation_v1(_a)
 
 #endif /* _SUDO_FATAL_H_ */
diff --git a/lib/util/Makefile.in b/lib/util/Makefile.in
index a65f86325..f495a95bb 100644
--- a/lib/util/Makefile.in
+++ b/lib/util/Makefile.in
@@ -98,7 +98,7 @@ SHELL = @SHELL@
 LTOBJS = alloc.lo event.lo fatal.lo key_val.lo gidlist.lo lbuf.lo locking.lo \
 	 parseln.lo progname.lo secure_path.lo setgroups.lo strtobool.lo \
 	 strtoid.lo strtomode.lo sudo_conf.lo sudo_debug.lo sudo_dso.lo \
-	 sudo_printf.lo term.lo ttysize.lo @COMMON_OBJS@ @LTLIBOBJS@
+	 term.lo ttysize.lo @COMMON_OBJS@ @LTLIBOBJS@
 
 ATOFOO_TEST_OBJS = atofoo_test.lo locale_stub.lo
 
@@ -494,10 +494,6 @@ sudo_debug.lo: $(srcdir)/sudo_debug.c $(incdir)/compat/stdbool.h \
 sudo_dso.lo: $(srcdir)/sudo_dso.c $(incdir)/sudo_compat.h $(incdir)/sudo_dso.h \
              $(top_builddir)/config.h
 	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sudo_dso.c
-sudo_printf.lo: $(srcdir)/sudo_printf.c $(incdir)/sudo_compat.h \
-                $(incdir)/sudo_debug.h $(incdir)/sudo_plugin.h \
-                $(top_builddir)/config.h
-	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sudo_printf.c
 term.lo: $(srcdir)/term.c $(incdir)/compat/stdbool.h $(incdir)/sudo_compat.h \
          $(incdir)/sudo_debug.h $(incdir)/sudo_util.h $(top_builddir)/config.h
 	$(LIBTOOL) --mode=compile $(CC) -c -o $@ $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/term.c
diff --git a/lib/util/fatal.c b/lib/util/fatal.c
index f337c002c..15d1f8b70 100644
--- a/lib/util/fatal.c
+++ b/lib/util/fatal.c
@@ -44,7 +44,8 @@ struct sudo_fatal_callback {
 };
 SLIST_HEAD(sudo_fatal_callback_list, sudo_fatal_callback);
 
-static struct sudo_fatal_callback_list callbacks;
+static struct sudo_fatal_callback_list callbacks = SLIST_HEAD_INITIALIZER(&callbacks);
+static sudo_conv_t sudo_warn_conversation;
 
 static void _warning(int errnum, const char *fmt, va_list ap);
 
@@ -135,24 +136,44 @@ sudo_vwarnx_nodebug_v1(const char *fmt, va_list ap)
 static void
 _warning(int errnum, const char *fmt, va_list ap)
 {
-    char *str;
+    if (sudo_warn_conversation != NULL) {
+	struct sudo_conv_message msgs[6];
+	int nmsgs = 0;
+	char *str = NULL;
 
-    sudo_evasprintf(&str, fmt, ap);
-    if (errnum) {
-	if (fmt != NULL) {
-	    sudo_printf(SUDO_CONV_ERROR_MSG,
-		_("%s: %s: %s\n"), getprogname(), str,
-		sudo_warn_strerror(errnum));
-	} else {
-	    sudo_printf(SUDO_CONV_ERROR_MSG,
-		_("%s: %s\n"), getprogname(),
-		sudo_warn_strerror(errnum));
-	}
+	/* Use conversation function. */
+        msgs[nmsgs].msg_type = SUDO_CONV_ERROR_MSG;
+	msgs[nmsgs++].msg = getprogname();
+        if (fmt != NULL) {
+		sudo_evasprintf(&str, fmt, ap);
+		msgs[nmsgs].msg_type = SUDO_CONV_ERROR_MSG;
+		msgs[nmsgs++].msg = ": ";
+		msgs[nmsgs].msg_type = SUDO_CONV_ERROR_MSG;
+		msgs[nmsgs++].msg = str;
+        }
+        if (errnum) {
+	    msgs[nmsgs].msg_type = SUDO_CONV_ERROR_MSG;
+	    msgs[nmsgs++].msg = ": ";
+	    msgs[nmsgs].msg_type = SUDO_CONV_ERROR_MSG;
+	    msgs[nmsgs++].msg = sudo_warn_strerror(errnum);
+        }
+	msgs[nmsgs].msg_type = SUDO_CONV_ERROR_MSG;
+	msgs[nmsgs++].msg = "\n";
+	sudo_warn_conversation(nmsgs, msgs, NULL);
+	sudo_efree(str);
     } else {
-	sudo_printf(SUDO_CONV_ERROR_MSG,
-	    _("%s: %s\n"), getprogname(), str ? str : "(null)");
+	/* Write to the standard error. */
+        fputs(getprogname(), stderr);
+        if (fmt != NULL) {
+                fputs(": ", stderr);
+                vfprintf(stderr, fmt, ap);
+        }
+        if (errnum) {
+            fputs(": ", stderr);
+            fputs(sudo_warn_strerror(errnum), stderr);
+        }
+        putc('\n', stderr);
     }
-    sudo_efree(str);
 }
 
 /*
@@ -201,3 +222,13 @@ sudo_fatal_callback_deregister_v1(sudo_fatal_callback_t func)
 
     return -1;
 }
+
+/*
+ * Set the conversation function to use for output insteaf of the
+ * standard error.  If conv is NULL, switch back to standard error.
+ */
+void
+sudo_warn_set_conversation_v1(sudo_conv_t conv)
+{
+    sudo_warn_conversation = conv;
+}
diff --git a/lib/util/util.exp.in b/lib/util/util.exp.in
index 9e308f795..4ee154930 100644
--- a/lib/util/util.exp.in
+++ b/lib/util/util.exp.in
@@ -1,4 +1,4 @@
-@COMPAT_EXP@_sudo_printf
+@COMPAT_EXP@
 initprogname
 sudo_conf_askpass_path_v1
 sudo_conf_debug_flags_v1
@@ -70,7 +70,6 @@ sudo_lock_file_v1
 sudo_new_key_val_v1
 sudo_parse_gids_v1
 sudo_parseln_v1
-sudo_printf
 sudo_secure_dir_v1
 sudo_secure_file_v1
 sudo_setgroups_v1
@@ -90,3 +89,4 @@ sudo_vwarn_nodebug_v1
 sudo_vwarnx_nodebug_v1
 sudo_warn_nodebug_v1
 sudo_warnx_nodebug_v1
+sudo_warn_set_conversation_v1
diff --git a/plugins/sudoers/Makefile.in b/plugins/sudoers/Makefile.in
index 487314bc2..6fce1a49c 100644
--- a/plugins/sudoers/Makefile.in
+++ b/plugins/sudoers/Makefile.in
@@ -138,7 +138,7 @@ AUTH_OBJS = sudo_auth.lo @AUTH_OBJS@
 
 LIBPARSESUDOERS_OBJS = alias.lo audit.lo base64.lo defaults.lo hexchar.lo \
 		       gram.lo match.lo match_addr.lo pwutil.lo pwutil_impl.lo \
-		       timestr.lo toke.lo toke_util.lo redblack.lo
+		       redblack.lo timestr.lo toke.lo toke_util.lo
 
 SUDOERS_OBJS = $(AUTH_OBJS) boottime.lo check.lo env.lo find_path.lo \
 	       goodpath.lo group_plugin.lo interfaces.lo iolog.lo \
@@ -146,14 +146,15 @@ SUDOERS_OBJS = $(AUTH_OBJS) boottime.lo check.lo env.lo find_path.lo \
 	       policy.lo prompt.lo set_perms.lo sudo_nss.lo sudoers.lo \
 	       timestamp.lo @SUDOERS_OBJS@
 
-VISUDO_OBJS = find_path.o goodpath.o locale.o visudo.o visudo_json.o
+VISUDO_OBJS = find_path.o goodpath.o locale.o sudo_printf.o visudo.o \
+	      visudo_json.o
 
 REPLAY_OBJS = getdate.o locale.o sudoreplay.o
 
 TEST_OBJS = group_plugin.o interfaces.o locale.o net_ifs.o \
-	    testsudoers.o tsgetgrpw.o
+	    sudo_printf.o testsudoers.o tsgetgrpw.o
 
-CHECK_ADDR_OBJS = check_addr.o interfaces.o locale.o match_addr.o
+CHECK_ADDR_OBJS = check_addr.o interfaces.o locale.o match_addr.o sudo_printf.o
 
 CHECK_BASE64_OBJS = check_base64.o base64.o locale.o
 
@@ -896,6 +897,10 @@ sudo_nss.lo: $(srcdir)/sudo_nss.c $(devdir)/def_data.h \
              $(srcdir)/logging.h $(srcdir)/sudo_nss.h $(srcdir)/sudoers.h \
              $(top_builddir)/config.h $(top_builddir)/pathnames.h
 	$(LIBTOOL) --mode=compile $(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sudo_nss.c
+sudo_printf.o: $(srcdir)/sudo_printf.c $(incdir)/sudo_compat.h \
+               $(incdir)/sudo_debug.h $(incdir)/sudo_plugin.h \
+               $(top_builddir)/config.h
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) $(PIE_CFLAGS) $(SSP_CFLAGS) $(DEFS) $(srcdir)/sudo_printf.c
 sudoers.lo: $(srcdir)/sudoers.c $(devdir)/def_data.h \
             $(incdir)/compat/getaddrinfo.h $(incdir)/compat/stdbool.h \
             $(incdir)/sudo_alloc.h $(incdir)/sudo_compat.h \
diff --git a/lib/util/sudo_printf.c b/plugins/sudoers/sudo_printf.c
similarity index 95%
rename from lib/util/sudo_printf.c
rename to plugins/sudoers/sudo_printf.c
index 03d5ed15f..474e0e2a4 100644
--- a/lib/util/sudo_printf.c
+++ b/plugins/sudoers/sudo_printf.c
@@ -33,7 +33,7 @@
 #include "sudo_plugin.h"
 #include "sudo_debug.h"
 
-__dso_public int
+static int
 _sudo_printf(int msg_type, const char *fmt, ...)
 {
     va_list ap;
@@ -59,4 +59,4 @@ _sudo_printf(int msg_type, const char *fmt, ...)
     return len;
 }
 
-__dso_public sudo_printf_t sudo_printf = _sudo_printf;
+sudo_printf_t sudo_printf = _sudo_printf;
diff --git a/plugins/sudoers/sudoers.c b/plugins/sudoers/sudoers.c
index 8a3a84171..bce4fa5e3 100644
--- a/plugins/sudoers/sudoers.c
+++ b/plugins/sudoers/sudoers.c
@@ -104,6 +104,7 @@ uid_t timestamp_uid;
 char *login_style;
 #endif /* HAVE_BSD_AUTH_H */
 int sudo_mode;
+sudo_printf_t sudo_printf;
 
 static char *prev_user;
 static char *runas_user;
diff --git a/plugins/sudoers/sudoers.h b/plugins/sudoers/sudoers.h
index d04201592..e13fec60e 100644
--- a/plugins/sudoers/sudoers.h
+++ b/plugins/sudoers/sudoers.h
@@ -364,6 +364,7 @@ extern int long_list;
 extern int sudo_mode;
 extern uid_t timestamp_uid;
 extern sudo_conv_t sudo_conv;
+extern sudo_printf_t sudo_printf;
 #endif
 
 #endif /* _SUDOERS_SUDOERS_H */
diff --git a/src/conversation.c b/src/conversation.c
index b23a41874..f48deac89 100644
--- a/src/conversation.c
+++ b/src/conversation.c
@@ -111,3 +111,29 @@ err:
 
     return -1;
 }
+
+int
+sudo_conversation_printf(int msg_type, const char *fmt, ...)
+{
+    va_list ap;
+    int len;
+
+    switch (msg_type) {
+    case SUDO_CONV_INFO_MSG:
+	va_start(ap, fmt);
+	len = vfprintf(stdout, fmt, ap);
+	va_end(ap);
+	break;
+    case SUDO_CONV_ERROR_MSG:
+	va_start(ap, fmt);
+	len = vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	break;
+    default:
+	len = -1;
+	errno = EINVAL;
+	break;
+    }
+
+    return len;
+}
diff --git a/src/sudo.c b/src/sudo.c
index 164014c41..05d5214a5 100644
--- a/src/sudo.c
+++ b/src/sudo.c
@@ -168,6 +168,9 @@ main(int argc, char *argv[], char *envp[])
 # endif
 #endif /* HAVE_GETPRPWNAM && HAVE_SET_AUTH_PARAMETERS */
 
+    /* Use conversation function for sudo_(warn|fatal)x?. */
+    sudo_warn_set_conversation(sudo_conversation);
+
     /* Make sure we are setuid root. */
     sudo_check_suid(argv[0]);
 
@@ -1085,11 +1088,13 @@ policy_open(struct plugin_container *plugin, char * const settings[],
     case SUDO_API_MKVERSION(1, 0):
     case SUDO_API_MKVERSION(1, 1):
 	rval = plugin->u.policy_1_0->open(plugin->u.io_1_0->version,
-	    sudo_conversation, _sudo_printf, settings, user_info, user_env);
+	    sudo_conversation, sudo_conversation_printf, settings,
+	    user_info, user_env);
 	break;
     default:
 	rval = plugin->u.policy->open(SUDO_API_VERSION, sudo_conversation,
-	    _sudo_printf, settings, user_info, user_env, plugin->options);
+	    sudo_conversation_printf, settings, user_info, user_env,
+	    plugin->options);
     }
 
     debug_return_bool(rval);
@@ -1205,17 +1210,17 @@ iolog_open(struct plugin_container *plugin, char * const settings[],
     switch (plugin->u.generic->version) {
     case SUDO_API_MKVERSION(1, 0):
 	rval = plugin->u.io_1_0->open(plugin->u.io_1_0->version,
-	    sudo_conversation, _sudo_printf, settings, user_info, argc, argv,
-	    user_env);
+	    sudo_conversation, sudo_conversation_printf, settings,
+	    user_info, argc, argv, user_env);
 	break;
     case SUDO_API_MKVERSION(1, 1):
 	rval = plugin->u.io_1_1->open(plugin->u.io_1_1->version,
-	    sudo_conversation, _sudo_printf, settings, user_info,
-	    command_info, argc, argv, user_env);
+	    sudo_conversation, sudo_conversation_printf, settings,
+	    user_info, command_info, argc, argv, user_env);
 	break;
     default:
 	rval = plugin->u.io->open(SUDO_API_VERSION, sudo_conversation,
-	    _sudo_printf, settings, user_info, command_info,
+	    sudo_conversation_printf, settings, user_info, command_info,
 	    argc, argv, user_env, plugin->options);
     }
     debug_return_bool(rval);
diff --git a/src/sudo_plugin_int.h b/src/sudo_plugin_int.h
index a1d3e9baa..2e0fb1709 100644
--- a/src/sudo_plugin_int.h
+++ b/src/sudo_plugin_int.h
@@ -101,7 +101,7 @@ extern struct plugin_container_list io_plugins;
 
 int sudo_conversation(int num_msgs, const struct sudo_conv_message msgs[],
     struct sudo_conv_reply replies[]);
-int _sudo_printf(int msg_type, const char *fmt, ...);
+int sudo_conversation_printf(int msg_type, const char *fmt, ...);
 
 bool sudo_load_plugins(struct plugin_container *policy_plugin,
     struct plugin_container_list *io_plugins);