diff --git a/configure.ac b/configure.ac
index 9a51ea1f7ed..dd2adb7e740 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1900,7 +1900,8 @@ tmp_CPPFLAGS="$CPPFLAGS"
 tmp_CFLAGS="$CFLAGS"
 CPPFLAGS="$CPPFLAGS -x objective-c"
 CFLAGS="$CFLAGS -x objective-c"
-GNU_OBJC_CFLAGS=
+# Recent versions of GCC don't use C99 to compile Obj-C.
+GNU_OBJC_CFLAGS="-std=c99"
 LIBS_GNUSTEP=
 if test "${with_ns}" != no; then
   # macfont.o requires macuvs.h which is absent after 'make extraclean',
@@ -1916,7 +1917,7 @@ if test "${with_ns}" != no; then
   elif flags=$( (gnustep-config --objc-flags) 2>/dev/null); then
      NS_IMPL_GNUSTEP=yes
      NS_GNUSTEP_CONFIG=yes
-     GNU_OBJC_CFLAGS=$flags
+     GNU_OBJC_CFLAGS="$GNU_OBJC_CFLAGS $flags"
      LIBS_GNUSTEP=$(gnustep-config --gui-libs) || exit
   elif test -f $GNUSTEP_CONFIG_FILE; then
      NS_IMPL_GNUSTEP=yes
@@ -1961,7 +1962,7 @@ fail;
        dnl _NATIVE_OBJC_EXCEPTIONS is used by the GNUstep headers.
        AC_DEFINE(_NATIVE_OBJC_EXCEPTIONS, 1,
          [Define if GNUstep uses ObjC exceptions.])
-       GNU_OBJC_CFLAGS="-fobjc-exceptions"
+       GNU_OBJC_CFLAGS="$GNU_OBJC_CFLAGS -fobjc-exceptions"
      fi
   fi
   if test $NS_IMPL_GNUSTEP = yes; then