diff --git a/docs/source/conf.py b/docs/source/conf.py
index 808aff6..4c397a4 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -27,7 +27,7 @@
 author = 'Justin Bousquin (US Environmental Protection Agency)'
 
 # ToDO:single source version
-version = "0.3.8"
+version = "0.4.0"
 #release = version(project)
 #release = harmonize_wq.__version__
 #version = '.'.join(release.split('.')[:2])