diff --git a/labs/abiquo/src/main/java/org/jclouds/abiquo/internal/BaseMonitoringService.java b/labs/abiquo/src/main/java/org/jclouds/abiquo/internal/BaseMonitoringService.java
index cacbf69372..a4a3c7dc13 100644
--- a/labs/abiquo/src/main/java/org/jclouds/abiquo/internal/BaseMonitoringService.java
+++ b/labs/abiquo/src/main/java/org/jclouds/abiquo/internal/BaseMonitoringService.java
@@ -176,8 +176,7 @@ public class BaseMonitoringService implements MonitoringService {
     * Performs the periodical monitoring tasks.
     * 
     * @author Ignasi Barrera
-    * @param <T>
-    *           The type of the object being monitored.
+    * @param <T> The type of the object being monitored.
     */
    @VisibleForTesting
    class AsyncMonitor<T> implements Runnable {
@@ -205,10 +204,13 @@ public class BaseMonitoringService implements MonitoringService {
       /**
        * Starts the monitoring job with the given timeout.
        * 
-       * @param maxWait
-       *           The timeout.
+       * @param maxWait The timeout.
+       * @param timeUnit The timeunit used in the maxWait parameter.
        */
       public void startMonitoring(final Long maxWait, TimeUnit timeUnit) {
+         if (maxWait != null) {
+            checkNotNull(timeUnit, "timeUnit must not be null when using timeouts");
+         }
          future = scheduler.scheduleWithFixedDelay(this, 0L, pollingDelay, TimeUnit.MILLISECONDS);
          timeout = maxWait == null ? null : System.currentTimeMillis() + timeUnit.toMillis(maxWait);
          logger.debug("started monitor job for %s with %s timeout", monitoredObject,
diff --git a/labs/abiquo/src/test/java/org/jclouds/abiquo/internal/AsyncMonitorTest.java b/labs/abiquo/src/test/java/org/jclouds/abiquo/internal/AsyncMonitorTest.java
index e3d3cea08d..e42cba3619 100644
--- a/labs/abiquo/src/test/java/org/jclouds/abiquo/internal/AsyncMonitorTest.java
+++ b/labs/abiquo/src/test/java/org/jclouds/abiquo/internal/AsyncMonitorTest.java
@@ -78,6 +78,42 @@ public class AsyncMonitorTest {
       verify(schedulerMock);
    }
 
+   @Test(expectedExceptions = NullPointerException.class, expectedExceptionsMessageRegExp = "timeUnit must not be null when using timeouts")
+   public void testStartMonitoringWithNullTimeout() {
+      ScheduledExecutorService schedulerMock = EasyMock.createMock(ScheduledExecutorService.class);
+      AsyncMonitor<Object> monitor = mockMonitor(schedulerMock, new Object(), mockFunction(MonitorStatus.DONE),
+            new EventBus());
+
+      monitor.startMonitoring(100L, null);
+   }
+
+   @SuppressWarnings({ "rawtypes", "unchecked" })
+   public void testStartMonitoringWithoutTimeoutAndNullTimeUnit() {
+      ScheduledFuture mockFuture = EasyMock.createMock(ScheduledFuture.class);
+      ScheduledExecutorService schedulerMock = EasyMock.createMock(ScheduledExecutorService.class);
+      expect(
+            schedulerMock.scheduleWithFixedDelay(anyObject(Runnable.class), anyLong(), anyLong(),
+                  anyObject(TimeUnit.class))).andReturn(mockFuture);
+
+      replay(mockFuture);
+      replay(schedulerMock);
+
+      AsyncMonitor<Object> monitor = mockMonitor(schedulerMock, new Object(), mockFunction(MonitorStatus.DONE),
+            new EventBus());
+
+      assertNull(monitor.getFuture());
+      assertNull(monitor.getTimeout());
+
+      // If the maxWait parameter is null, timeUnit is not required
+      monitor.startMonitoring(null, null);
+
+      assertNotNull(monitor.getFuture());
+      assertNull(monitor.getTimeout());
+
+      verify(mockFuture);
+      verify(schedulerMock);
+   }
+
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public void testStartMonitoringWithTimeout() {
       ScheduledFuture mockFuture = EasyMock.createMock(ScheduledFuture.class);
@@ -105,6 +141,33 @@ public class AsyncMonitorTest {
       verify(schedulerMock);
    }
 
+   @SuppressWarnings({ "rawtypes", "unchecked" })
+   public void testStartMonitoringWithTimeoutInMinutes() {
+      ScheduledFuture mockFuture = EasyMock.createMock(ScheduledFuture.class);
+      ScheduledExecutorService schedulerMock = EasyMock.createMock(ScheduledExecutorService.class);
+      expect(
+            schedulerMock.scheduleWithFixedDelay(anyObject(Runnable.class), anyLong(), anyLong(),
+                  anyObject(TimeUnit.class))).andReturn(mockFuture);
+
+      replay(mockFuture);
+      replay(schedulerMock);
+
+      AsyncMonitor<Object> monitor = mockMonitor(schedulerMock, new Object(), mockFunction(MonitorStatus.DONE),
+            new EventBus());
+
+      assertNull(monitor.getFuture());
+      assertNull(monitor.getTimeout());
+
+      monitor.startMonitoring(1L, TimeUnit.MINUTES);
+
+      assertNotNull(monitor.getFuture());
+      assertNotNull(monitor.getTimeout());
+      assertTrue(monitor.getTimeout() > TimeUnit.MINUTES.toMillis(1));
+
+      verify(mockFuture);
+      verify(schedulerMock);
+   }
+
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public void testIsTimeoutWhenNullTimeout() {
       ScheduledFuture mockFuture = EasyMock.createMock(ScheduledFuture.class);