diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index 76dad17e33..5ddc30c19c 100644
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -406,9 +406,7 @@ find_base_rel(PlannerInfo *root, int relid)
 {
 	RelOptInfo *rel;
 
-	Assert(relid > 0);
-
-	if (relid < root->simple_rel_array_size)
+	if (relid > 0 && relid < root->simple_rel_array_size)
 	{
 		rel = root->simple_rel_array[relid];
 		if (rel)