diff --git a/src/qibo/models/circuit.py b/src/qibo/models/circuit.py
index fb038a54e3..4aff6fd184 100644
--- a/src/qibo/models/circuit.py
+++ b/src/qibo/models/circuit.py
@@ -87,7 +87,7 @@ def from_fused(self):
 
     @property
     def nmeasurements(self):
-        return len([1 for gate in self if isinstance(gate, gates.M)])
+        return len(list(filter(lambda gate: isinstance(gate, gates.M), self)))
 
     @property
     def moments(self):