diff --git a/src/eval.c b/src/eval.c
index 8e55435..9fb3b4e 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1462,6 +1462,13 @@
 		semsg(_(e_dictkey), lp->ll_newkey);
 		return;
 	    }
+	    if ((lp->ll_tv->vval.v_dict == get_globvar_dict()
+		    || lp->ll_tv->vval.v_dict ==
+			   &SCRIPT_ITEM(current_sctx.sc_sid)->sn_vars->sv_dict)
+		    && (rettv->v_type == VAR_FUNC
+			|| rettv->v_type == VAR_PARTIAL)
+		    && var_wrong_func_name(lp->ll_newkey, TRUE))
+		return;
 
 	    // Need to add an item to the Dictionary.
 	    di = dictitem_alloc(lp->ll_newkey);
diff --git a/src/testdir/test_functions.vim b/src/testdir/test_functions.vim
index 4337606..e1aff61 100644
--- a/src/testdir/test_functions.vim
+++ b/src/testdir/test_functions.vim
@@ -2681,4 +2681,12 @@
   call assert_fails('call gettext(1)', 'E475:')
 endfunc
 
+func Test_builtin_check()
+  call assert_fails('let g:["trim"] = {x -> " " .. x}', 'E704:')
+  call assert_fails('let g:.trim = {x -> " " .. x}', 'E704:')
+  call assert_fails('let s:["trim"] = {x -> " " .. x}', 'E704:')
+  call assert_fails('let s:.trim = {x -> " " .. x}', 'E704:')
+endfunc
+
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/version.c b/src/version.c
index 099d05a..c1fdb64 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2918,
+/**/
     2917,
 /**/
     2916,