diff --git a/src/mlpack/tests/logistic_regression_test.cpp b/src/mlpack/tests/logistic_regression_test.cpp
index ff358a8ee9..82c62f8315 100644
--- a/src/mlpack/tests/logistic_regression_test.cpp
+++ b/src/mlpack/tests/logistic_regression_test.cpp
@@ -262,4 +262,80 @@ BOOST_AUTO_TEST_CASE(LogisticRegressionFunctionRegularizationSeparableEvaluate)
   }
 }
 
+/**
+ * Test separable gradient of the LogisticRegressionFunction.
+ */
+BOOST_AUTO_TEST_CASE(LogisticRegressionFunctionSeparableGradient)
+{
+  // Very simple fake dataset.
+  arma::mat data("1 1 1;" // Fake row for intercept.
+                 "1 2 3;"
+                 "1 2 3");
+  arma::vec responses("1 1 0");
+
+  // Create a LogisticRegressionFunction.
+  LogisticRegressionFunction lrf(data, responses, 0.0 /* no regularization */);
+  arma::vec gradient;
+
+  // If the model is at the optimum, then the gradient should be zero.
+  lrf.Gradient(arma::vec("200 -40 -40"), 0, gradient);
+
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_SMALL(gradient[0], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[1], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[2], 1e-15);
+
+  lrf.Gradient(arma::vec("200 -40 -40"), 1, gradient);
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_SMALL(gradient[0], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[1], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[2], 1e-15);
+
+  lrf.Gradient(arma::vec("200 -40 -40"), 2, gradient);
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_SMALL(gradient[0], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[1], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[2], 1e-15);
+
+  // Perturb two elements in the wrong way, so they need to become smaller.  For
+  // the first two data points, classification is still correct so the gradient
+  // should be zero.
+  lrf.Gradient(arma::vec("200 -30 -30"), 0, gradient);
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_SMALL(gradient[0], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[1], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[2], 1e-15);
+
+  lrf.Gradient(arma::vec("200 -30 -30"), 1, gradient);
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_SMALL(gradient[0], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[1], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[2], 1e-15);
+
+  lrf.Gradient(arma::vec("200 -30 -30"), 2, gradient);
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_GE(gradient[1], 0.0);
+  BOOST_REQUIRE_GE(gradient[2], 0.0);
+
+  // Perturb two elements in the other wrong way, so they need to become larger.
+  // For the first and last data point, classification is still correct so the
+  // gradient should be zero.
+  lrf.Gradient(arma::vec("200 -60 -60"), 0, gradient);
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_SMALL(gradient[0], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[1], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[2], 1e-15);
+
+  lrf.Gradient(arma::vec("200 -30 -30"), 1, gradient);
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_LE(gradient[1], 0.0);
+  BOOST_REQUIRE_LE(gradient[2], 0.0);
+
+  lrf.Gradient(arma::vec("200 -60 -60"), 2, gradient);
+  BOOST_REQUIRE_EQUAL(gradient.n_elem, 3);
+  BOOST_REQUIRE_SMALL(gradient[0], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[1], 1e-15);
+  BOOST_REQUIRE_SMALL(gradient[2], 1e-15);
+}
+
 BOOST_AUTO_TEST_SUITE_END();