diff --git a/tests/ref/basic.list b/tests/ref/basic.list
index 71b929c1835..31b512cec4d 100644
--- a/tests/ref/basic.list
+++ b/tests/ref/basic.list
@@ -1,4 +1,4 @@
-# This file is must be sorted alphabetically.
+# This file must be sorted alphabetically.
 # Please run `./mach test-tidy` to check your changes.