diff --git a/version.h b/version.h
index 6084b95073..71197f55dc 100644
--- a/version.h
+++ b/version.h
@@ -4,7 +4,7 @@
 
 #define RUBY_RELEASE_YEAR 2018
 #define RUBY_RELEASE_MONTH 12
-#define RUBY_RELEASE_DAY 14
+#define RUBY_RELEASE_DAY 15
 
 #include "ruby/version.h"