diff --git a/src/qibo/backends/numpy.py b/src/qibo/backends/numpy.py
index 67de27b2f3..d99fc873d0 100644
--- a/src/qibo/backends/numpy.py
+++ b/src/qibo/backends/numpy.py
@@ -440,7 +440,11 @@ def execute_circuit_repeated(self, circuit, initial_state=None, nshots=None):
 
         if not circuit.density_matrix:
             samples = []
-            probabilities = np.zeros(2**nqubits, dtype=float)
+            target_qubits = [
+                measurement.target_qubits for measurement in circuit.measurements
+            ]
+            target_qubits = sum(target_qubits, tuple())
+            probabilities = np.zeros(2 ** len(target_qubits), dtype=float)
             probabilities = self.cast(probabilities, dtype=probabilities.dtype)
 
         for _ in range(nshots):