diff --git a/stringtie.cpp b/stringtie.cpp
index f7aae70..2daadc3 100644
--- a/stringtie.cpp
+++ b/stringtie.cpp
@@ -11,7 +11,7 @@
 #include "proc_mem.h"
 #endif
 
-#define VERSION "2.1.3"
+#define VERSION "2.1.3b"
 
 //#define DEBUGPRINT 1