diff --git a/src/mlpack/methods/softmax_regression/softmax_regression.hpp b/src/mlpack/methods/softmax_regression/softmax_regression.hpp
index a2c8ee39ee..e08466b35d 100644
--- a/src/mlpack/methods/softmax_regression/softmax_regression.hpp
+++ b/src/mlpack/methods/softmax_regression/softmax_regression.hpp
@@ -121,7 +121,8 @@ class SoftmaxRegression
    * @param testData Matrix of data points using which predictions are made.
    * @param labels Vector of labels associated with the data.
    */
-  double ComputeAccuracy(const arma::mat& testData, const arma::Row<size_t>& labels);
+  double ComputeAccuracy(const arma::mat& testData,
+                         const arma::Row<size_t>& labels) const;
 
   /**
    * Train the softmax regression model with the given optimizer.
diff --git a/src/mlpack/methods/softmax_regression/softmax_regression_impl.hpp b/src/mlpack/methods/softmax_regression/softmax_regression_impl.hpp
index d3c8fe976e..dfede6e50e 100644
--- a/src/mlpack/methods/softmax_regression/softmax_regression_impl.hpp
+++ b/src/mlpack/methods/softmax_regression/softmax_regression_impl.hpp
@@ -117,7 +117,7 @@ void SoftmaxRegression<OptimizerType>::Predict(const arma::mat& testData,
 template<template<typename> class OptimizerType>
 double SoftmaxRegression<OptimizerType>::ComputeAccuracy(
     const arma::mat& testData,
-    const arma::Row<size_t>& labels)
+    const arma::Row<size_t>& labels) const
 {
   arma::Row<size_t> predictions;