diff --git a/tests/net/java/com/android/server/NsdServiceTest.java b/tests/net/java/com/android/server/NsdServiceTest.java
index 2e49c98..b88c784 100644
--- a/tests/net/java/com/android/server/NsdServiceTest.java
+++ b/tests/net/java/com/android/server/NsdServiceTest.java
@@ -77,7 +77,10 @@
 
     @After
     public void tearDown() throws Exception {
-        mThread.quit();
+        if (mThread != null) {
+            mThread.quit();
+            mThread = null;
+        }
     }
 
     @Test