diff --git a/GPy/kern/Matern32.py b/GPy/kern/Matern32.py
index a5d70a62..9831ae40 100644
--- a/GPy/kern/Matern32.py
+++ b/GPy/kern/Matern32.py
@@ -14,7 +14,7 @@ class Matern32(kernpart):
 
     .. math::
 
-       k(r) = \\sigma^2 (1 + \\sqrt{3} r) \exp(- \sqrt{3} r) \\ aa \\ \\ \\  \\text{ where  } r = \sqrt{\sum_{i=1}^D \\frac{(x_i-y_i)^2}{\ell_i^2} }
+       k(r) = \\sigma^2 (1 + \\sqrt{3} r) \exp(- \sqrt{3} r) \\ \\ \\ \\  \\text{ where  } r = \sqrt{\sum_{i=1}^D \\frac{(x_i-y_i)^2}{\ell_i^2} }
 
     :param D: the number of input dimensions
     :type D: int