diff --git a/src/mlpack/methods/ann/activation_functions/gaussian_function.hpp b/src/mlpack/methods/ann/activation_functions/gaussian_function.hpp
index 6bd9116e3a..dac5879763 100644
--- a/src/mlpack/methods/ann/activation_functions/gaussian_function.hpp
+++ b/src/mlpack/methods/ann/activation_functions/gaussian_function.hpp
@@ -60,7 +60,6 @@ class GaussianFunction
    */
   static double Deriv(const double x, const double y)
   {
-    // return 2 * -y * std::exp(-1 * std::pow(y, 2));
     return -2 * x * y;
   }