diff --git a/src/dict.c b/src/dict.c
index 5abb996..fc8756c 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -107,6 +107,8 @@
 dict_free_contents(dict_T *d)
 {
     hashtab_free_contents(&d->dv_hashtab);
+    free_type(d->dv_type);
+    d->dv_type = NULL;
 }
 
 /*
@@ -1057,6 +1059,12 @@
     hashitem_T	*hi2;
     int		todo;
     char_u	*arg_errmsg = (char_u *)N_("extend() argument");
+    type_T	*type;
+
+    if (d1->dv_type != NULL && d1->dv_type->tt_member != NULL)
+	type = d1->dv_type->tt_member;
+    else
+	type = NULL;
 
     todo = (int)d2->dv_hashtab.ht_used;
     for (hi2 = d2->dv_hashtab.ht_array; todo > 0; ++hi2)
@@ -1076,6 +1084,11 @@
 		if (!valid_varname(hi2->hi_key, TRUE))
 		    break;
 	    }
+
+	    if (type != NULL
+		     && check_typval_type(type, &HI2DI(hi2)->di_tv, 0) == FAIL)
+		break;
+
 	    if (di1 == NULL)
 	    {
 		di1 = dictitem_copy(HI2DI(hi2));