diff --git a/gwinc/ifo/noises.py b/gwinc/ifo/noises.py
index 56e06b1adc577508966f2d3db03f3a08675432f4..caf200a9cd0593a8b5fef1d8ec9b98fdfaf2068e 100644
--- a/gwinc/ifo/noises.py
+++ b/gwinc/ifo/noises.py
@@ -342,7 +342,7 @@ class ITMThermoRefractive(nb.Noise):
         w0, wBeam_ITM, wBeam_ETM = arm_cavity(self.ifo)
         n = noise.substratethermal.substrate_thermorefractive(
             self.freq, self.ifo.Materials, wBeam_ITM)
-        return n * 2 / (gPhase)**2
+        return n * 2 / gPhase**2
 
 
 class ITMCarrierDensity(nb.Noise):
@@ -361,7 +361,7 @@ class ITMCarrierDensity(nb.Noise):
         w0, wBeam_ITM, wBeam_ETM = arm_cavity(self.ifo)
         n = noise.substratethermal.substrate_carrierdensity(
             self.freq, self.ifo.Materials, wBeam_ITM)
-        return n * 2 / (gPhase)**2
+        return n * 2 / gPhase**2
 
 
 class SubstrateBrownian(nb.Noise):