diff --git a/atst/app.py b/atst/app.py
index 17063840..1bd86640 100644
--- a/atst/app.py
+++ b/atst/app.py
@@ -58,7 +58,7 @@ def make_flask_callbacks(app):
         }
 
     @app.template_filter('iconSvg')
-    def iconSvg(name):
+    def _iconSvg(name):
         with open('static/icons/'+name+'.svg') as contents:
             return contents.read()