diff --git a/ChangeLog b/ChangeLog
index e61df241e2..6422417fc6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Jul 26 01:37:45 2013  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* include/ruby/ruby.h: check defined(USE_RGENGC_LOGGING_WB_UNPROTECT)
+
 Fri Jul 26 01:21:41 2013  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* file.c (rb_file_expand_path_internal): fix r42160; skip '~'.
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 7bfc0b261c..575a2b61fc 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -1266,7 +1266,7 @@ void rb_gc_writebarrier_unprotect_promoted(VALUE obj);
 #define OBJ_WRITE(a, slot, b)       rb_obj_write((VALUE)(a), (VALUE *)(slot), (VALUE)(b), __FILE__, __LINE__)
 #define OBJ_WRITTEN(a, oldv, b)     rb_obj_written((VALUE)(a), (VALUE)(oldv), (VALUE)(b), __FILE__, __LINE__)
 
-#if USE_RGENGC_LOGGING_WB_UNPROTECT
+#if defined(USE_RGENGC_LOGGING_WB_UNPROTECT) && USE_RGENGC_LOGGING_WB_UNPROTECT
 void rb_gc_unprotect_logging(void *objptr, const char *filename, int line);
 #define RGENGC_LOGGING_WB_UNPROTECT rb_gc_unprotect_logging
 #endif