diff --git a/iiify/app.py b/iiify/app.py
index 778b53b..f0799e7 100755
--- a/iiify/app.py
+++ b/iiify/app.py
@@ -81,7 +81,7 @@ def documentation():
 
 @app.route('/iiif/helper/<identifier>/')
 def helper(identifier):
-    validate_ia_identifier(identifier, page_suffix=false)
+    validate_ia_identifier(identifier, page_suffix=False)
 
     metadata = requests.get('%s/metadata/%s' % (ARCHIVE, identifier)).json()