diff --git a/version.h b/version.h
index be34807d59..ab43225a3a 100644
--- a/version.h
+++ b/version.h
@@ -4,7 +4,7 @@
 
 #define RUBY_RELEASE_YEAR 2017
 #define RUBY_RELEASE_MONTH 12
-#define RUBY_RELEASE_DAY 12
+#define RUBY_RELEASE_DAY 13
 
 #include "ruby/version.h"