diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 766ca49216f0761b3edd985a78b992fec072cf27..83fb39fe18790e0a68ed61aec315929e0d89da9c 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2250,6 +2250,7 @@ _outRelOptInfo(StringInfo str, const RelOptInfo *node)
 	WRITE_UINT_FIELD(baserestrict_min_security);
 	WRITE_NODE_FIELD(joininfo);
 	WRITE_BOOL_FIELD(has_eclass_joins);
+	WRITE_BITMAPSET_FIELD(top_parent_relids);
 }
 
 static void