diff --git a/ChangeLog b/ChangeLog
index 88649bb133..285dbd15ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Aug  8 19:55:51 2013  Koichi Sasada  <ko1@atdot.net>
+
+	* include/ruby/ruby.h: define USE_RGENGC_LOGGING_WB_UNPROTECT.
+
 Thu Aug  8 16:44:25 2013  Koichi Sasada  <ko1@atdot.net>
 
 	* include/ruby/ruby.h: add old macro name `RUBY_EVENT_SWITCH'.
diff --git a/include/ruby/ruby.h b/include/ruby/ruby.h
index 9410c4c0e6..abcc73b5b3 100644
--- a/include/ruby/ruby.h
+++ b/include/ruby/ruby.h
@@ -1266,7 +1266,11 @@ 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 defined(USE_RGENGC_LOGGING_WB_UNPROTECT) && USE_RGENGC_LOGGING_WB_UNPROTECT
+#ifndef USE_RGENGC_LOGGING_WB_UNPROTECT
+#define USE_RGENGC_LOGGING_WB_UNPROTECT 0
+#endif
+
+#if 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