diff --git a/scripts/gcc-plugins/gcc-common.h b/scripts/gcc-plugins/gcc-common.h
index 552d5ef..17f0607 100644
--- a/scripts/gcc-plugins/gcc-common.h
+++ b/scripts/gcc-plugins/gcc-common.h
@@ -150,8 +150,12 @@
 void dump_gimple_stmt(pretty_printer *, gimple, int, int);
 #endif
 
+#ifndef __unused
 #define __unused __attribute__((__unused__))
+#endif
+#ifndef __visible
 #define __visible __attribute__((visibility("default")))
+#endif
 
 #define DECL_NAME_POINTER(node) IDENTIFIER_POINTER(DECL_NAME(node))
 #define DECL_NAME_LENGTH(node) IDENTIFIER_LENGTH(DECL_NAME(node))