diff --git a/pyfive/__init__.py b/pyfive/__init__.py
index 9df950e..1427b78 100644
--- a/pyfive/__init__.py
+++ b/pyfive/__init__.py
@@ -4,4 +4,4 @@
 
 from .high_level import File
 
-__version__ = '0.4.0.dev'
+__version__ = '0.4.0'