diff --git a/version.h b/version.h
index 7b03c1fe07..ea8551270d 100644
--- a/version.h
+++ b/version.h
@@ -16,7 +16,7 @@
 
 #define RUBY_RELEASE_YEAR 2021
 #define RUBY_RELEASE_MONTH 5
-#define RUBY_RELEASE_DAY 8
+#define RUBY_RELEASE_DAY 9
 
 #include "ruby/version.h"