diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 738c178107..98366a2d5b 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -15095,6 +15095,7 @@ ATExecDetachPartition(Relation rel, RangeVar *name)
 	{
 		Oid			idxid = lfirst_oid(cell);
 		Relation	idx;
+		bool		detachConstraint = false;
 		Oid			constrOid;
 
 		if (!has_superclass(idxid))
@@ -15106,14 +15107,18 @@ ATExecDetachPartition(Relation rel, RangeVar *name)
 		idx = index_open(idxid, AccessExclusiveLock);
 		IndexSetParentIndex(idx, InvalidOid);
 		update_relispartition(classRel, idxid, false);
-		index_close(idx, NoLock);
 
 		/*
 		 * Detach any constraints associated with the index too.  Only UNIQUE
 		 * and PRIMARY KEY index constraints can be inherited, so no need
 		 * to check for others.
 		 */
-		if (!idx->rd_index->indisprimary && !idx->rd_index->indisunique)
+		if (idx->rd_index->indisprimary || idx->rd_index->indisunique)
+			detachConstraint = true;
+
+		index_close(idx, NoLock);
+
+		if (!detachConstraint)
 			continue;
 
 		constrOid = get_relation_idx_constraint_oid(RelationGetRelid(partRel),