diff --git a/configure.ac b/configure.ac
index e887ddd3bf..50247ca545 100644
--- a/configure.ac
+++ b/configure.ac
@@ -626,6 +626,9 @@ AS_IF([test "$GCC" = yes], [
     ],
     [
       # ANSI (no XCFLAGS because this is C only)
+      rb_tmp_std_check=`echo $CC $CFLAGS $optflags $warnflags $debugflags | fgrep std= | tr -d  '\015'`
+      AS_IF([test "x$rb_tmp_std_check" = "x"],
+      [
 	for ansi_options in -std=gnu99; do
 	    RUBY_TRY_CFLAGS(${ansi_options}, [
 		RUBY_APPEND_OPTIONS(warnflags, ${ansi_options})
@@ -633,6 +636,7 @@ AS_IF([test "$GCC" = yes], [
 	    ], [ansi_options=])
 	    test "x${ansi_options}" = x || break
 	done
+      ])
     ])
 
     # suppress annoying -Wstrict-overflow warnings