diff --git a/src/qibolab/_core/instruments/qm/controller.py b/src/qibolab/_core/instruments/qm/controller.py
index 805196556..ed06c9531 100644
--- a/src/qibolab/_core/instruments/qm/controller.py
+++ b/src/qibolab/_core/instruments/qm/controller.py
@@ -331,7 +331,9 @@ def register_pulses(self, configs: dict[str, Config], sequence: PulseSequence):
             acquisitions (dict): Map from measurement instructions to acquisition objects.
         """
         for id, pulse in sequence:
-            if hasattr(pulse, "duration") and not pulse.duration.is_integer():
+            if hasattr(pulse, "duration") and not (
+                isinstance(pulse.duration, int) or pulse.duration.is_integer()
+            ):
                 raise ValueError(
                     f"Quantum Machines cannot play pulse with duration {pulse.duration}. "
                     "Only integer duration in ns is supported."