diff --git a/bilby/gw/detector/interferometer.py b/bilby/gw/detector/interferometer.py
index 4f54b71579eefe878cb6039a5c543e515a7f315f..ac0c148861f6e6c7f084fc3a4d91b872d729ca74 100644
--- a/bilby/gw/detector/interferometer.py
+++ b/bilby/gw/detector/interferometer.py
@@ -645,7 +645,7 @@ class Interferometer(object):
         Such that
 
         .. math::
-            Var(n) = \\frac{1}{N} \\sum_k=0^N n_W(f_k)n_W^*(f_k) = 2
+            Var(n) = \\frac{1}{N} \\sum_{k=0}^N n_W(f_k)n_W^*(f_k) = 2
 
         Where the factor of two is due to the independent real and imaginary
         components.
@@ -678,12 +678,12 @@ class Interferometer(object):
 
         .. math::
 
-            W = \\frac{1}{N} \\sum_{k=0}^N \\Theta(f_{max} - f_k)\\Theta(f_k - f_{min})}
+            W = \\frac{1}{N} \\sum_{k=0}^N \\Theta(f_{max} - f_k)\\Theta(f_k - f_{min})
 
         and accordingly the termwise window factor is
 
         .. math::
-            w = \\sqrt{N W} = \\sqrt{\\sum_{k=0}^N \\Theta(f_{max} - f_k)\\Theta(f_k - f_{min})}}
+            w = \\sqrt{N W} = \\sqrt{\\sum_{k=0}^N \\Theta(f_{max} - f_k)\\Theta(f_k - f_{min})}
 
         """
         frequency_window_factor = (