diff --git a/configure b/configure
index 04e98042bb..62c43ba92b 100755
--- a/configure
+++ b/configure
@@ -29860,7 +29860,20 @@ if test "$WCSLEN_FOUND" = 1; then
 
 fi
 
-for ac_func in wcsdup wcsftime strnlen wcsnlen wcscasecmp wcsncasecmp
+for ac_func in strnlen
+do :
+  ac_fn_c_check_func "$LINENO" "strnlen" "ac_cv_func_strnlen"
+if test "x$ac_cv_func_strnlen" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_STRNLEN 1
+_ACEOF
+
+fi
+done
+
+
+if test "$wxUSE_MAC" != 1; then
+    for ac_func in wcsdup wcsftime wcsnlen wcscasecmp wcsncasecmp
 do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
 ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
@@ -29872,6 +29885,7 @@ _ACEOF
 fi
 done
 
+fi
 
 if test "$USE_HPUX" = 1 -a "$GCC" != "yes"; then
     CPPFLAGS="-D_INCLUDE__STDC_A1_SOURCE $CPPFLAGS"
diff --git a/configure.in b/configure.in
index d2193e4992..e420dd5be5 100644
--- a/configure.in
+++ b/configure.in
@@ -4095,7 +4095,16 @@ if test "$WCSLEN_FOUND" = 1; then
     AC_DEFINE(HAVE_WCSLEN)
 fi
 
-AC_CHECK_FUNCS([wcsdup wcsftime strnlen wcsnlen wcscasecmp wcsncasecmp])
+AC_CHECK_FUNCS(strnlen)
+
+dnl OS X provides the wide character functions starting from 10.7 so our tests
+dnl would succeed if we're configuring under 10.7 or later, yet the compiled
+dnl programs would fail if ran under 10.6 or earlier. To avoid this problem we
+dnl define the corresponding HAVE_XXX in wx/osx/config_xcode.h instead of
+dnl testing for them here.
+if test "$wxUSE_MAC" != 1; then
+    AC_CHECK_FUNCS([wcsdup wcsftime wcsnlen wcscasecmp wcsncasecmp])
+fi
 
 dnl On HP-UX aCC need this define to find mbstrtowcs() &c
 dnl Can't be used for g++ since the mbstate_t in wchar.h can conflict
diff --git a/include/wx/osx/config_xcode.h b/include/wx/osx/config_xcode.h
index 0174f32707..006fef025b 100644
--- a/include/wx/osx/config_xcode.h
+++ b/include/wx/osx/config_xcode.h
@@ -74,6 +74,17 @@
 #define HAVE_VSSCANF_DECL 1
 #define HAVE_USLEEP 1
 #define HAVE_WCSLEN 1
+
+/* Many wchar functions are only available since 10.7 so don't use them if we
+   want to build the applications that would run under 10.6 and earlier. */
+#if MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_X_VERSION_10_7
+#define HAVE_WCSDUP 1
+#define HAVE_WCSFTIME 1
+#define HAVE_WCSNLEN 1
+#define HAVE_WCSCASECMP 1
+#define HAVE_WCSNCASECMP 1
+#endif
+
 #define SIZEOF_WCHAR_T 4
 #define SIZEOF_SHORT 2
 #define SIZEOF_INT 4