diff --git a/src/version.h b/src/version.h
index fe243d75d9..67eb15527e 100644
--- a/src/version.h
+++ b/src/version.h
@@ -1 +1 @@
-#define LAMMPS_VERSION "3 May 2011"
+#define LAMMPS_VERSION "4 May 2011"