diff --git a/jsprit-core/src/test/java/com/graphhopper/jsprit/core/util/UnassignedJobReasonTrackerTest.java b/jsprit-core/src/test/java/com/graphhopper/jsprit/core/util/UnassignedJobReasonTrackerTest.java
index 7b975e9a..0b8f639f 100644
--- a/jsprit-core/src/test/java/com/graphhopper/jsprit/core/util/UnassignedJobReasonTrackerTest.java
+++ b/jsprit-core/src/test/java/com/graphhopper/jsprit/core/util/UnassignedJobReasonTrackerTest.java
@@ -134,6 +134,19 @@ public class UnassignedJobReasonTrackerTest {
         Assert.assertEquals(4, reasonTracker.getMostLikelyReasonCode(solution.getUnassignedJobs().iterator().next().getId()));
     }
 
+    @Test
+    public void getMostLikelyTest() {
+        Frequency frequency = new Frequency();
+        frequency.addValue("a");
+        frequency.addValue("b");
+        frequency.addValue("a");
+        frequency.addValue("a");
+        frequency.addValue("a");
+        frequency.addValue("a");
+        frequency.addValue("a");
+        Assert.assertEquals("a", UnassignedJobReasonTracker.getMostLikelyFailedConstraintName(frequency));
+    }
+
     @Test
     public void testFreq() {
         Frequency frequency = new Frequency();