diff --git a/src/pint/models/noise_model.py b/src/pint/models/noise_model.py
index b1af8e10f..299787fe5 100644
--- a/src/pint/models/noise_model.py
+++ b/src/pint/models/noise_model.py
@@ -164,14 +164,14 @@ def scale_toa_sigma(self, toas, warn=True):
             if equad.quantity is None:
                 continue
             mask = equad.select_toa_mask(toas)
-            if np.any(mask):
+            if len(mask) > 0:
                 sigma_scaled[mask] = np.hypot(sigma_scaled[mask], equad.quantity)
             elif warn:
                 warnings.warn(f"EQUAD {equad} has no TOAs")
         for efac_name in self.EFACs:
             efac = getattr(self, efac_name)
             mask = efac.select_toa_mask(toas)
-            if np.any(mask):
+            if len(mask) > 0:
                 sigma_scaled[mask] *= efac.quantity
             elif warn:
                 warnings.warn(f"EFAC {efac} has no TOAs")