diff --git a/libcxx/include/list b/libcxx/include/list
--- a/libcxx/include/list
+++ b/libcxx/include/list
@@ -2099,6 +2099,9 @@
     _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__f) == &__c,
         "list::splice(iterator, list, iterator, iterator) called with second iterator not"
         " referring to list argument");
+    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__l) == &__c,
+        "list::splice(iterator, list, iterator, iterator) called with third iterator not"
+        " referring to list argument");
     if (this == &__c)
     {
         for (const_iterator __i = __f; __i != __l; ++__i)