2 files changed, 7 insertions, 3 deletions
diff --git a/ChangeLog b/ChangeLog
index 8b176afdf9..53ae9fdb81 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri May 20 22:30:09 2016  Naohisa Goto  <ngotogenome@gmail.com>
+
+	* symbol.h (rb_id2sym): Use HAVE_BUILTIN___BUILTIN_CONSTANT_P
+
 Fri May 20 22:19:00 2016  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
 
 	* ext/date/date_core.c: [DOC] fix typos.
diff --git a/symbol.h b/symbol.h
index 641b9792ed..1f0b139811 100644
--- a/symbol.h
+++ b/symbol.h
@@ -17,10 +17,10 @@
 #define DYNAMIC_ID_P(id) (!(id&ID_STATIC_SYM)&&id>tLAST_OP_ID)
 #define STATIC_ID2SYM(id)  (((VALUE)(id)<<RUBY_SPECIAL_SHIFT)|SYMBOL_FLAG)
 
-#ifdef __GNUC__
+#ifdef HAVE_BUILTIN___BUILTIN_CONSTANT_P
 #define rb_id2sym(id) \
-    __extension__(__builtin_constant_p(id) && !DYNAMIC_ID_P(id) ? \
-		  STATIC_ID2SYM(id) : rb_id2sym(id))
+    RB_GNUC_EXTENSION_BLOCK(__builtin_constant_p(id) && !DYNAMIC_ID_P(id) ? \
+			    STATIC_ID2SYM(id) : rb_id2sym(id))
 #endif
 
 struct RSymbol {