diff --git a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
index 89a55a7..b9ed56a 100644
--- a/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
+++ b/tests/cts/hostside/app/src/com/android/cts/net/hostside/AbstractRestrictBackgroundNetworkTestCase.java
@@ -198,7 +198,8 @@
     protected void tearDown() throws Exception {
         executeShellCommand("cmd netpolicy stop-watching");
         mServiceClient.unbind();
-        if (mLock.isHeld()) mLock.release();
+        final PowerManager.WakeLock lock = mLock;
+        if (null != lock && lock.isHeld()) lock.release();
     }
 
     protected int getUid(String packageName) throws Exception {