diff --git a/src/qutip_qip/circuit/circuitsimulator.py b/src/qutip_qip/circuit/circuitsimulator.py
index 435c0e16..5ecb0555 100644
--- a/src/qutip_qip/circuit/circuitsimulator.py
+++ b/src/qutip_qip/circuit/circuitsimulator.py
@@ -561,7 +561,7 @@ def _check_classical_control_value(operation, cbits):
                 apply_gate = True
             if apply_gate:
                 state = self._evolve_state(
-                    operation, current_state, expand=True
+                    operation, current_state
                 )
             else:
                 state = current_state
@@ -573,7 +573,7 @@ def _check_classical_control_value(operation, cbits):
         self._state = state
         return state
 
-    def _evolve_state(self, operation, state, expand=False):
+    def _evolve_state(self, operation, state):
         """
         Applies unitary to state.