diff --git a/ext/gd/config.m4 b/ext/gd/config.m4
index 014826f775d..2da4f5318e4 100644
--- a/ext/gd/config.m4
+++ b/ext/gd/config.m4
@@ -153,6 +153,7 @@ dnl A whole whack of possible places where this might be
   AC_CHECK_LIB(gd, gdImageString16, [ AC_DEFINE(HAVE_LIBGD13,1, [ ]) ])
   if test "$ac_cv_lib_gd_gdImageLine" = "yes"; then
 		old_LIBS=$LIBS
+	        old_LDFLAGS=$LDFLAGS
         AC_CHECK_LIB(gd, gdImageString16, [ AC_DEFINE(HAVE_LIBGD13,1, [ ]) ])
 		AC_CHECK_LIB(z,compress, LIBS="-lz $LIBS",,)
 		AC_CHECK_LIB(png,png_info_init, LIBS="-lpng $LIBS",,)