diff --git a/config.h.in b/config.h.in
index 8626973ac..5066ca563 100644
--- a/config.h.in
+++ b/config.h.in
@@ -848,6 +848,9 @@
 /* Define to 1 if you have the `strsignal' function. */
 #undef HAVE_STRSIGNAL
 
+/* Define to 1 if you have the `strtoull' function. */
+#undef HAVE_STRTOULL
+
 /* Define to 1 if `d_namlen' is a member of `struct dirent'. */
 #undef HAVE_STRUCT_DIRENT_D_NAMLEN
 
diff --git a/configure b/configure
index 1a7342d70..fa4469cfb 100755
--- a/configure
+++ b/configure
@@ -3254,6 +3254,7 @@ as_fn_append ac_func_c_list " nl_langinfo HAVE_NL_LANGINFO"
 as_fn_append ac_func_c_list " faccessat HAVE_FACCESSAT"
 as_fn_append ac_func_c_list " wordexp HAVE_WORDEXP"
 as_fn_append ac_func_c_list " getauxval HAVE_GETAUXVAL"
+as_fn_append ac_func_c_list " strtoull HAVE_STRTOULL"
 as_fn_append ac_func_c_list " seteuid HAVE_SETEUID"
 
 # Auxiliary files required by this configure script.
@@ -21009,6 +21010,7 @@ done
 
 
 
+
   for ac_func in execvpe
 do :
   ac_fn_c_check_func "$LINENO" "execvpe" "ac_cv_func_execvpe"
diff --git a/configure.ac b/configure.ac
index 85efd8d5f..4744b83fe 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2560,7 +2560,7 @@ dnl Function checks
 dnl
 AC_FUNC_GETGROUPS
 AC_FUNC_FSEEKO
-AC_CHECK_FUNCS_ONCE([fexecve fmemopen killpg nl_langinfo faccessat wordexp getauxval])
+AC_CHECK_FUNCS_ONCE([fexecve fmemopen killpg nl_langinfo faccessat wordexp getauxval strtoull])
 AC_CHECK_FUNCS([execvpe], [SUDO_APPEND_INTERCEPT_EXP(execvpe)])
 AC_CHECK_FUNCS([pread], [
     # pread/pwrite on 32-bit HP-UX 11.x may not support large files
diff --git a/plugins/sudoers/defaults.c b/plugins/sudoers/defaults.c
index d9eda17f4..869f8230f 100644
--- a/plugins/sudoers/defaults.c
+++ b/plugins/sudoers/defaults.c
@@ -876,11 +876,16 @@ check_rlimit(const char *str, bool soft)
 	unsigned long long ullval;
 	char *ep;
 
-	/* XXX - some systems may lack strtoull() */
 	errno = 0;
+#ifdef HAVE_STRTOULL
 	ullval = strtoull(str, &ep, 10);
 	if (str == ep || (errno == ERANGE && ullval == ULLONG_MAX))
 	    debug_return_bool(false);
+#else
+	ullval = strtoul(str, &ep, 10);
+	if (str == ep || (errno == ERANGE && ullval == ULONG_MAX))
+	    debug_return_bool(false);
+#endif
 	if (*ep == '\0' || (soft && *ep == ','))
 	    debug_return_bool(true);
 	debug_return_bool(false);
diff --git a/src/limits.c b/src/limits.c
index 9e1dbb5cf..525e09c82 100644
--- a/src/limits.c
+++ b/src/limits.c
@@ -457,11 +457,16 @@ store_rlimit(const char *str, rlim_t *val, bool soft)
 	unsigned long long ullval = 0;
 	char *ep;
 
-	/* XXX - some systems may lack strtoull() */
 	errno = 0;
+#ifdef HAVE_STRTOULL
 	ullval = strtoull(str, &ep, 10);
 	if (str == ep || (errno == ERANGE && ullval == ULLONG_MAX))
 	    debug_return_bool(false);
+#else
+	ullval = strtoul(str, &ep, 10);
+	if (str == ep || (errno == ERANGE && ullval == ULONG_MAX))
+	    debug_return_bool(false);
+#endif
 	if (*ep == '\0' || (soft && *ep == ',')) {
 	    *val = ullval;
 	    debug_return_bool(true);