diff --git a/mrbgems/mruby-version/src/version.h b/mrbgems/mruby-version/src/version.h
index 5ca3f3d59..69fbef0fa 100644
--- a/mrbgems/mruby-version/src/version.h
+++ b/mrbgems/mruby-version/src/version.h
@@ -7,7 +7,7 @@
 #define MRUBY_RELEASE_MONTH 1
 #define MRUBY_RELEASE_DAY 10
 
-#define MRUBY_BIRTH_YEAR 2011
+#define MRUBY_BIRTH_YEAR 2010
 
 #define MRUBY_AUTHOR "mruby developers"