diff --git a/qiskit/transpiler/passes/layout/vf2_layout.py b/qiskit/transpiler/passes/layout/vf2_layout.py
index ec23ac90eb2b..3cb0dbf8a6a0 100644
--- a/qiskit/transpiler/passes/layout/vf2_layout.py
+++ b/qiskit/transpiler/passes/layout/vf2_layout.py
@@ -211,9 +211,10 @@ def _score_layout(self, layout):
         on the chosen qubits. If BackendProperties are not available it uses the coupling map degree
         to weight against higher connectivity qubits."""
         bits = layout.get_physical_bits()
-        score = 0
+        score = None
         if self.target is not None:
             if "measure" in self.target:
+                score = 0
                 for bit in bits:
                     props = self.target["measure"].get((bit,))
                     if props is None or props.error is None:
@@ -223,7 +224,8 @@ def _score_layout(self, layout):
                         ) / len(self.coupling_map.graph)
                     else:
                         score += props.error
-        else:
+        if score is None:
+            score = 0
             if self.properties is None:
                 # Sum qubit degree for each qubit in chosen layout as really rough estimate of error
                 for bit in bits: