diff --git a/parallel_hashmap/btree.h b/parallel_hashmap/btree.h
index 3452f90..74eaf1e 100644
--- a/parallel_hashmap/btree.h
+++ b/parallel_hashmap/btree.h
@@ -713,7 +713,7 @@ namespace phmap {
         template <
             typename Compare, typename K, typename LK,
             phmap::enable_if_t<!std::is_same<bool, phmap::invoke_result_t<
-                                                       Compare(const K &, const LK &)>>::value,
+                                                       Compare, const K &, const LK &>>::value,
                                int> = 0>
             constexpr phmap::weak_ordering do_three_way_comparison(const Compare &compare,
                                                                    const K &x, const LK &y) {
@@ -721,8 +721,8 @@ namespace phmap {
         }
         template <
             typename Compare, typename K, typename LK,
-            phmap::enable_if_t<std::is_same<bool, phmap::invoke_result_t<Compare(
-            const K &, const LK &)>>::value,
+            phmap::enable_if_t<std::is_same<bool, phmap::invoke_result_t<Compare,
+            const K &, const LK &>>::value,
                                int> = 0>
             constexpr phmap::weak_ordering do_three_way_comparison(const Compare &compare,
                                                                    const K &x, const LK &y) {