diff --git a/cool_seq_tool/version.py b/cool_seq_tool/version.py
index 9fa4000e..061f84a6 100644
--- a/cool_seq_tool/version.py
+++ b/cool_seq_tool/version.py
@@ -1,2 +1,2 @@
 """Define package version."""
-__version__ = "0.4.0-dev0"
+__version__ = "0.4.0-dev1"