src/backend/catalog/namespace.c | 8 ++++++++
 1 file changed, 8 insertions(+)
diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 740570c566..a7f38baf6e 100644
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -2989,6 +2989,11 @@ CheckSetNamespace(Oid oldNspOid, Oid nspOid)
  *
  * Note: calling this may result in a CommandCounterIncrement operation,
  * if we have to create or clean out the temp namespace.
+ *
+ * This function acquires AccessShareLock on the target
+ * namespace. Without this, the namespace could be dropped before our
+ * transaction commits, leaving behind objects with relnamespace pointing
+ * to a no-longer-existent namespace.
  */
 Oid
 QualifiedNameGetCreationNamespace(List *names, char **objname_p)
@@ -3029,6 +3034,9 @@ QualifiedNameGetCreationNamespace(List *names, char **objname_p)
 					 errmsg("no schema has been selected to create in")));
 	}
 
+	/* Lock namespace. */
+	LockDatabaseObject(NamespaceRelationId, namespaceId, 0, AccessShareLock);
+
 	return namespaceId;
 }