diff --git a/mtools/version.py b/mtools/version.py
index 2d640ef0..870d16dc 100644
--- a/mtools/version.py
+++ b/mtools/version.py
@@ -1,4 +1,4 @@
 #!/bin/python
 """Mtools version."""
 
-__version__ = '1.5.2'
+__version__ = '1.5.3-dev'