diff --git a/services/core/java/com/android/server/am/BatteryExternalStatsWorker.java b/services/core/java/com/android/server/am/BatteryExternalStatsWorker.java
index 702526a4beabe..1a0d291d375c4 100644
--- a/services/core/java/com/android/server/am/BatteryExternalStatsWorker.java
+++ b/services/core/java/com/android/server/am/BatteryExternalStatsWorker.java
@@ -399,7 +399,7 @@ class BatteryExternalStatsWorker implements BatteryStatsImpl.ExternalStatsSync {
         }
     }
 
-    public void shutdown() {
+    public synchronized void shutdown() {
         mExecutorService.shutdownNow();
     }