diff --git a/tests/Fixtures/functions/include/sandbox.test b/tests/Fixtures/functions/include/sandbox.test
index ebfdb1eb8ff..ec7e61e9703 100644
--- a/tests/Fixtures/functions/include/sandbox.test
+++ b/tests/Fixtures/functions/include/sandbox.test
@@ -5,8 +5,8 @@
 --TEMPLATE(foo.twig)--
 
 
-{{ foo|e }}
-{{ foo|e }}
+{{ 'foo'|e }}
+{{ 'foo'|e }}
 --DATA--
 return []
 --EXCEPTION--