diff --git a/webbpsf_ext/version.py b/webbpsf_ext/version.py
index 46e19cc..1dcbd2c 100644
--- a/webbpsf_ext/version.py
+++ b/webbpsf_ext/version.py
@@ -2,4 +2,4 @@
 
 __author__  = """Jarron Leisenring"""
 __email__   = 'jarronl@email.arizona.edu'
-__version__ = u'1.2.1'
+__version__ = u'1.2.1dev'