diff --git a/include/nuttx/compiler.h b/include/nuttx/compiler.h
index c5610df5972cd..5f287297d465e 100644
--- a/include/nuttx/compiler.h
+++ b/include/nuttx/compiler.h
@@ -1110,6 +1110,14 @@
 
 #endif
 
+/* Green Hills Software definitions *****************************************/
+
+#if defined(__ghs__)
+
+#  define __extension__
+
+#endif
+
 #ifndef CONFIG_HAVE_LONG_LONG
 #  undef CONFIG_FS_LARGEFILE
 #endif