diff --git a/services/core/java/com/android/server/display/WakelockController.java b/services/core/java/com/android/server/display/WakelockController.java
index 6511f4f4fa84d..1e13974f6ef4a 100644
--- a/services/core/java/com/android/server/display/WakelockController.java
+++ b/services/core/java/com/android/server/display/WakelockController.java
@@ -38,7 +38,9 @@ public final class WakelockController {
     public static final int WAKE_LOCK_STATE_CHANGED = 4;
     public static final int WAKE_LOCK_UNFINISHED_BUSINESS = 5;
 
-    private static final int WAKE_LOCK_MAX = WAKE_LOCK_UNFINISHED_BUSINESS;
+    @VisibleForTesting
+    static final int WAKE_LOCK_MAX = WAKE_LOCK_UNFINISHED_BUSINESS;
+
     private static final boolean DEBUG = false;
 
     @IntDef(flag = true, prefix = "WAKE_LOCK_", value = {
@@ -132,7 +134,7 @@ public final class WakelockController {
      * A utility to release all the wakelock acquired by the system
      */
     public void releaseAll() {
-        for (int i = WAKE_LOCK_PROXIMITY_POSITIVE; i < WAKE_LOCK_MAX; i++) {
+        for (int i = WAKE_LOCK_PROXIMITY_POSITIVE; i <= WAKE_LOCK_MAX; i++) {
             releaseWakelockInternal(i);
         }
     }
diff --git a/services/tests/mockingservicestests/src/com/android/server/display/WakelockControllerTest.java b/services/tests/mockingservicestests/src/com/android/server/display/WakelockControllerTest.java
index 07a81ffb8e18d..c23d4b19cd3ac 100644
--- a/services/tests/mockingservicestests/src/com/android/server/display/WakelockControllerTest.java
+++ b/services/tests/mockingservicestests/src/com/android/server/display/WakelockControllerTest.java
@@ -244,6 +244,15 @@ public final class WakelockControllerTest {
         verifyZeroInteractions(mDisplayPowerCallbacks);
     }
 
+    @Test
+    public void testReleaseAll() throws Exception {
+        // Use WAKE_LOCK_MAX to verify it has been correctly set and used in releaseAll().
+        verifyWakelockAcquisition(WakelockController.WAKE_LOCK_MAX,
+                () -> mWakelockController.hasUnfinishedBusiness());
+        mWakelockController.releaseAll();
+        assertFalse(mWakelockController.hasUnfinishedBusiness());
+    }
+
     private void verifyWakelockAcquisitionAndReaquisition(int wakelockId,
             Callable<Boolean> isWakelockAcquiredCallable)
             throws Exception {
@@ -284,6 +293,4 @@ public final class WakelockControllerTest {
         assertFalse(mWakelockController.releaseWakelock(wakelockId));
         assertFalse(isWakelockAcquiredCallable.call());
     }
-
-
 }