diff --git a/setup.py b/setup.py
index 0412138..760c429 100644
--- a/setup.py
+++ b/setup.py
@@ -46,9 +46,9 @@ except FileNotFoundError:
     long_description = DESCRIPTION
 
 # Load the package's __version__.py module as a dictionary.
-project_slug = NAME.lower().replace("-", "_").replace(" ", "_")
 about = {}
 if not VERSION:
+    project_slug = NAME.lower().replace("-", "_").replace(" ", "_")
     with open(os.path.join(here, project_slug, '__version__.py')) as f:
         exec(f.read(), about)
 else: