diff --git a/yellowstone/config.py b/yellowstone/config.py
index abba1ce..8644c45 100644
--- a/yellowstone/config.py
+++ b/yellowstone/config.py
@@ -50,6 +50,6 @@ def uses_admin_members(self, site_slug: str) -> bool:
 
 def getenv(var_name) -> str:
     value = os.getenv(var_name)
-    if not value:
+    if value is None:
         raise RuntimeError(f"No value for environment variable {var_name}")
     return value