diff --git a/solr/core/src/test/org/apache/solr/util/TimeOutTest.java b/solr/core/src/test/org/apache/solr/util/TimeOutTest.java
new file mode 100644
index 00000000000..c7d38fa7923
--- /dev/null
+++ b/solr/core/src/test/org/apache/solr/util/TimeOutTest.java
@@ -0,0 +1,66 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.solr.util;
+
+import static java.util.concurrent.TimeUnit.NANOSECONDS;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import org.apache.solr.SolrTestCaseJ4;
+import org.apache.solr.common.util.TimeSource;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class TimeOutTest extends SolrTestCaseJ4 {
+  private static TimeSource mockTimeSource;
+
+  @BeforeClass
+  public static void setUpOnce() {
+    assumeWorkingMockito();
+  }
+
+  @Before
+  public void timeSourceMock() {
+    mockTimeSource = mock(TimeSource.class);
+    when(mockTimeSource.getTimeNs()).thenReturn(Long.valueOf(10)).thenReturn(Long.valueOf(50));
+  }
+
+  @Test
+  public void testHasTimedOut() {
+    TimeOut timeOut = new TimeOut(20, NANOSECONDS, mockTimeSource);
+    assertTrue(timeOut.hasTimedOut());
+  }
+
+  @Test
+  public void testHasNotTimedOut() {
+    TimeOut timeOut = new TimeOut(100, NANOSECONDS, mockTimeSource);
+    assertFalse(timeOut.hasTimedOut());
+  }
+
+  @Test
+  public void testTimeLeft() {
+    TimeOut timeOut = new TimeOut(240, NANOSECONDS, mockTimeSource);
+    assertEquals(timeOut.timeLeft(NANOSECONDS), 200);
+  }
+
+  @Test
+  public void testTimeElapsed() {
+    TimeOut timeOut = new TimeOut(100, NANOSECONDS, mockTimeSource);
+    assertEquals(timeOut.timeElapsed(NANOSECONDS), 40);
+  }
+}