diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index e02945008e232e944ee5d71d7fc626f234190859..82166e06965b428a715e4fab42195c9d18e46f2d 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -7620,6 +7620,7 @@ class LUInstanceRename(LogicalUnit):
     # Change the instance lock. This is definitely safe while we hold the BGL.
     # Otherwise the new lock would have to be added in acquired mode.
     assert self.REQ_BGL
+    assert self.glm.is_owned(locking.BGL)
     self.glm.remove(locking.LEVEL_INSTANCE, old_name)
     self.glm.add(locking.LEVEL_INSTANCE, self.op.new_name)