diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/fitting/leastsquares/AbstractLeastSquaresOptimizerAbstractTest.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/fitting/leastsquares/AbstractLeastSquaresOptimizerAbstractTest.java
index d601c865f..00fc3bb88 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/fitting/leastsquares/AbstractLeastSquaresOptimizerAbstractTest.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/fitting/leastsquares/AbstractLeastSquaresOptimizerAbstractTest.java
@@ -39,10 +39,6 @@ import org.junit.Test;
 import java.io.IOException;
 import java.util.Arrays;
 
-import static org.hamcrest.CoreMatchers.is;
-import static org.hamcrest.CoreMatchers.not;
-import static org.hamcrest.CoreMatchers.sameInstance;
-
 /**
  * Some of the unit tests are re-implementations of the MINPACK <a
  * href="http://www.netlib.org/minpack/ex/file17">file17</a> and <a
@@ -549,9 +545,7 @@ public abstract class AbstractLeastSquaresOptimizerAbstractTest {
                 .checker(new ConvergenceChecker<Evaluation>() {
                     @Override
                     public boolean converged(int iteration, Evaluation previous, Evaluation current) {
-                        Assert.assertThat(
-                                previous.getPoint(),
-                                not(sameInstance(current.getPoint())));
+                        Assert.assertFalse(previous.getPoint().equals(current.getPoint()));
                         Assert.assertArrayEquals(new double[3], previous.getPoint().toArray(), 0);
                         Assert.assertArrayEquals(new double[] {1, 2, 3}, current.getPoint().toArray(), TOL);
                         checked[0] = true;
@@ -560,7 +554,7 @@ public abstract class AbstractLeastSquaresOptimizerAbstractTest {
                 });
         optimizer.optimize(builder.build());
 
-        Assert.assertThat(checked[0], is(true));
+        Assert.assertTrue(checked[0]);
     }
 
     class LinearProblem {
diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/fitting/leastsquares/LevenbergMarquardtOptimizerTest.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/fitting/leastsquares/LevenbergMarquardtOptimizerTest.java
index aedeed856..64e8969b3 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/fitting/leastsquares/LevenbergMarquardtOptimizerTest.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/fitting/leastsquares/LevenbergMarquardtOptimizerTest.java
@@ -32,8 +32,6 @@ import org.apache.commons.numbers.core.Precision;
 import org.junit.Assert;
 import org.junit.Test;
 
-import static org.hamcrest.CoreMatchers.is;
-
 /**
  * <p>Some of the unit tests are re-implementations of the MINPACK <a
  * href="http://www.netlib.org/minpack/ex/file17">file17</a> and <a
@@ -339,8 +337,7 @@ public class LevenbergMarquardtOptimizerTest
 
         //verify
         //check iterations and evaluations are not switched.
-        Assert.assertThat(optimum.getIterations(), is(1));
-        Assert.assertThat(optimum.getEvaluations(), is(2));
+        Assert.assertEquals(1, optimum.getIterations());
+        Assert.assertEquals(2, optimum.getEvaluations());
     }
-
 }
diff --git a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/ml/clustering/FuzzyKMeansClustererTest.java b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/ml/clustering/FuzzyKMeansClustererTest.java
index 6e4b67295..cf100973f 100644
--- a/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/ml/clustering/FuzzyKMeansClustererTest.java
+++ b/commons-math-legacy/src/test/java/org/apache/commons/math4/legacy/ml/clustering/FuzzyKMeansClustererTest.java
@@ -26,7 +26,6 @@ import org.apache.commons.math4.legacy.ml.distance.CanberraDistance;
 import org.apache.commons.math4.legacy.ml.distance.DistanceMeasure;
 import org.apache.commons.rng.simple.RandomSource;
 import org.apache.commons.rng.UniformRandomProvider;
-import org.hamcrest.CoreMatchers;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -101,8 +100,8 @@ public class FuzzyKMeansClustererTest {
         Assert.assertEquals(2.0, clusterer.getFuzziness(), 1e-6);
         Assert.assertEquals(100, clusterer.getMaxIterations());
         Assert.assertEquals(1e-6, clusterer.getEpsilon(), 1e-12);
-        Assert.assertThat(clusterer.getDistanceMeasure(), CoreMatchers.is(measure));
-        Assert.assertThat(clusterer.getRandomGenerator(), CoreMatchers.is(random));
+        Assert.assertEquals(measure, clusterer.getDistanceMeasure());
+        Assert.assertEquals(random, clusterer.getRandomGenerator());
     }
 
     @Test