diff --git a/src/qibo/result.py b/src/qibo/result.py
index 905cbb8e49..91fef766b8 100644
--- a/src/qibo/result.py
+++ b/src/qibo/result.py
@@ -326,7 +326,9 @@ def samples(self, binary: bool = True, registers: bool = False):
             if self.measurements[0].result.has_samples():
                 self._samples = self.backend.np.concatenate(
                     [
-                        self.backend.cast(gate.result.samples())
+                        self.backend.cast(
+                            gate.result.samples(), dtype=self.backend.np.int32
+                        )
                         for gate in self.measurements
                     ],
                     axis=1,