diff --git a/version.h b/version.h
index 27f7fe7684..f228782ef9 100644
--- a/version.h
+++ b/version.h
@@ -1,5 +1,5 @@
 #define RUBY_VERSION "1.9.1"
-#define RUBY_RELEASE_DATE "2008-12-17"
+#define RUBY_RELEASE_DATE "2008-12-18"
 #define RUBY_PATCHLEVEL 5000
 
 #define RUBY_VERSION_MAJOR 1
@@ -7,7 +7,7 @@
 #define RUBY_VERSION_TEENY 1
 #define RUBY_RELEASE_YEAR 2008
 #define RUBY_RELEASE_MONTH 12
-#define RUBY_RELEASE_DAY 17
+#define RUBY_RELEASE_DAY 18
 
 #ifdef RUBY_EXTERN
 RUBY_EXTERN const char ruby_version[];