diff --git a/Include/patchlevel.h b/Include/patchlevel.h
index 97b767a7fd8..41e400a9816 100644
--- a/Include/patchlevel.h
+++ b/Include/patchlevel.h
@@ -1 +1 @@
-#define PATCHLEVEL "1.5a4"
+#define PATCHLEVEL "1.5b1"