diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index cd6c275c639..01b2d6d2d4a 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -1466,7 +1466,10 @@ _outPathInfo(StringInfo str, Path *node)
 {
 	WRITE_ENUM_FIELD(pathtype, NodeTag);
 	appendStringInfo(str, " :parent_relids ");
-	_outBitmapset(str, node->parent->relids);
+	if (node->parent)
+		_outBitmapset(str, node->parent->relids);
+	else
+		_outBitmapset(str, NULL);
 	WRITE_FLOAT_FIELD(startup_cost, "%.2f");
 	WRITE_FLOAT_FIELD(total_cost, "%.2f");
 	WRITE_NODE_FIELD(pathkeys);