diff --git a/core/src/main/java/jenkins/slaves/DefaultJnlpSlaveReceiver.java b/core/src/main/java/jenkins/slaves/DefaultJnlpSlaveReceiver.java
index 1011db9334d714104c7ce79b97ce25f850a7e059..4d213f35e4b933797d1ddd67f2752cae498d0135 100644
--- a/core/src/main/java/jenkins/slaves/DefaultJnlpSlaveReceiver.java
+++ b/core/src/main/java/jenkins/slaves/DefaultJnlpSlaveReceiver.java
@@ -48,7 +48,7 @@ public class DefaultJnlpSlaveReceiver extends JnlpAgentReceiver {
                 }
             } else {
                 handshake.error(nodeName + " is already connected to this master. Rejecting this connection.");
-                return false;
+                return true;
             }
         }
 
diff --git a/core/src/test/java/jenkins/slaves/DefaultJnlpSlaveReceiverTest.java b/core/src/test/java/jenkins/slaves/DefaultJnlpSlaveReceiverTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..9cc6425d34b11b1017b8291896b5df2705d6b273
--- /dev/null
+++ b/core/src/test/java/jenkins/slaves/DefaultJnlpSlaveReceiverTest.java
@@ -0,0 +1,142 @@
+package jenkins.slaves;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+import static org.powermock.api.mockito.PowerMockito.mockStatic;
+
+import hudson.TcpSlaveAgentListener.ConnectionFromCurrentPeer;
+import hudson.remoting.Channel;
+import hudson.slaves.SlaveComputer;
+import jenkins.model.Jenkins;
+
+import java.io.IOException;
+import java.util.Properties;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+
+@RunWith(PowerMockRunner.class)
+@PrepareForTest(Jenkins.class)
+public class DefaultJnlpSlaveReceiverTest {
+
+    @Mock private Jenkins mockJenkins;
+    @Mock private SlaveComputer mockComputer;
+    @Mock private Channel mockChannel;
+    @Mock private JnlpSlaveAgentProtocol2.Handler mockHandshake;
+    @Mock private Future mockFuture;
+
+    private DefaultJnlpSlaveReceiver receiver;
+
+    @Before
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+
+        mockStatic(Jenkins.class);
+        when(Jenkins.getInstance()).thenReturn(mockJenkins);
+
+        receiver = new DefaultJnlpSlaveReceiver();
+    }
+
+    @Test
+    public void testHandle() throws Exception {
+        when(mockJenkins.getComputer("node")).thenReturn(mockComputer);
+        when(mockComputer.getChannel()).thenReturn(null);
+        when(mockChannel.getProperty(any(String.class))).thenReturn("some cookie");
+        when(mockHandshake.jnlpConnect(mockComputer)).thenReturn(mockChannel);
+
+        assertTrue(receiver.handle("node", mockHandshake));
+        verify(mockHandshake).success(any(Properties.class));
+        verify(mockChannel).setProperty(any(String.class), any(String.class));
+    }
+
+    @Test
+    public void testHandleWithInvalidNode() throws Exception {
+        when(mockJenkins.getComputer("bogus-node")).thenReturn(null);
+
+        assertFalse(receiver.handle("bogus-node", mockHandshake));
+    }
+
+    @Test
+    public void testHandleTakeover() throws Exception {
+        when(mockJenkins.getComputer("node")).thenReturn(mockComputer);
+        when(mockComputer.getChannel()).thenReturn(mockChannel);
+        when(mockHandshake.getRequestProperty(any(String.class))).thenReturn("some cookie");
+        when(mockChannel.getProperty(any(String.class))).thenReturn("some cookie");
+        when(mockComputer.disconnect(any(ConnectionFromCurrentPeer.class))).thenReturn(mockFuture);
+        when(mockHandshake.jnlpConnect(mockComputer)).thenReturn(mockChannel);
+
+        assertTrue(receiver.handle("node", mockHandshake));
+        verify(mockFuture).get(15, TimeUnit.SECONDS);
+        verify(mockHandshake).success(any(Properties.class));
+        verify(mockChannel).setProperty(any(String.class), any(String.class));
+    }
+
+    @Test
+    public void testHandleTakeoverFailedDisconnect() throws Exception {
+        when(mockJenkins.getComputer("node")).thenReturn(mockComputer);
+        when(mockComputer.getChannel()).thenReturn(mockChannel);
+        when(mockHandshake.getRequestProperty(any(String.class))).thenReturn("some cookie");
+        when(mockChannel.getProperty(any(String.class))).thenReturn("some cookie");
+        when(mockComputer.disconnect(any(ConnectionFromCurrentPeer.class))).thenReturn(mockFuture);
+        when(mockFuture.get(15, TimeUnit.SECONDS)).thenThrow(new ExecutionException(null));
+
+        try {
+            receiver.handle("node", mockHandshake);
+            fail();
+        } catch (IOException e) {
+            // good
+        }
+    }
+
+    @Test
+    public void testHandleTakeoverTimedOut() throws Exception {
+        when(mockJenkins.getComputer("node")).thenReturn(mockComputer);
+        when(mockComputer.getChannel()).thenReturn(mockChannel);
+        when(mockHandshake.getRequestProperty(any(String.class))).thenReturn("some cookie");
+        when(mockChannel.getProperty(any(String.class))).thenReturn("some cookie");
+        when(mockComputer.disconnect(any(ConnectionFromCurrentPeer.class))).thenReturn(mockFuture);
+        when(mockFuture.get(15, TimeUnit.SECONDS)).thenThrow(new TimeoutException());
+
+        try {
+            receiver.handle("node", mockHandshake);
+            fail();
+        } catch (IOException e) {
+            // good
+        }
+    }
+
+    @Test
+    public void testHandleAttemptTakeoverWithNullCookie() throws Exception {
+        when(mockJenkins.getComputer("node")).thenReturn(mockComputer);
+        when(mockComputer.getChannel()).thenReturn(mockChannel);
+        when(mockHandshake.getRequestProperty(any(String.class))).thenReturn(null);
+        when(mockChannel.getProperty(any(String.class))).thenReturn("some cookie");
+
+        assertTrue(receiver.handle("node", mockHandshake));
+        verify(mockHandshake).error(any(String.class));
+    }
+
+    @Test
+    public void testHandleAttemptTakeoverWithInvalidCookie() throws Exception {
+        when(mockJenkins.getComputer("node")).thenReturn(mockComputer);
+        when(mockComputer.getChannel()).thenReturn(mockChannel);
+        when(mockHandshake.getRequestProperty(any(String.class))).thenReturn("bogus cookie");
+        when(mockChannel.getProperty(any(String.class))).thenReturn("some cookie");
+
+        assertTrue(receiver.handle("node", mockHandshake));
+        verify(mockHandshake).error(any(String.class));
+    }
+}