diff --git a/tests/get-function.rs b/tests/get-function.rs
index bfd047d..757b0ec 100644
--- a/tests/get-function.rs
+++ b/tests/get-function.rs
@@ -46,6 +46,12 @@ test!(
     "a {b: get-function(lighten) == get-function(darken);}",
     "a {\n  b: false;\n}\n"
 );
+test!(
+    builtin_not_equal_to_user_defined,
+    "@function user-defined() {\n  @return foo;\n}\n
+    a {b: get-function(lighten) == get-function(user-defined);}",
+    "a {\n  b: false;\n}\n"
+);
 test!(
     inspect_builtin_function,
     "a {b: inspect(get-function(lighten));}",