diff --git a/src/subtype.c b/src/subtype.c
index 3b8cfce277df4..4aa8083b01371 100644
--- a/src/subtype.c
+++ b/src/subtype.c
@@ -3847,6 +3847,8 @@ JL_DLLEXPORT int jl_type_morespecific(jl_value_t *a, jl_value_t *b)
 {
     if (obviously_disjoint(a, b, 1))
         return 0;
+    if (jl_has_free_typevars(a) || jl_has_free_typevars(b))
+        return 0;
     if (jl_subtype(b, a))
         return 0;
     if (jl_subtype(a, b))