diff --git a/map2map/models/power.py b/map2map/models/power.py
index 9b72d2a..81fb7ac 100644
--- a/map2map/models/power.py
+++ b/map2map/models/power.py
@@ -19,10 +19,11 @@ def power(x):
 
     try:
         x = torch.fft.rfftn(x, s=signal_size)  # new version broke BC
+        P = x.real.square() + x.imag.square()
     except AttributeError:
         x = torch.rfft(x, signal_ndim)
+        P = x.square().sum(dim=-1)
 
-    P = x.pow(2).sum(dim=-1)
     P = P.mean(dim=0)
     P = P.sum(dim=0)
     del x