diff --git a/gas/config/ho-sunos.h b/gas/config/ho-sunos.h
index 180263245d..ef4b3cb154 100644
--- a/gas/config/ho-sunos.h
+++ b/gas/config/ho-sunos.h
@@ -9,6 +9,9 @@
 #else
 extern int memset();
 #endif
+
+/* #include <sys/stdtypes.h> before <stddef.h> when compiling by GCC.  */
+#include <sys/stdtypes.h>
 #include <stddef.h>
 #include <ctype.h>
 #include <string.h>