diff --git a/services/core/java/com/android/server/locksettings/LockSettingsService.java b/services/core/java/com/android/server/locksettings/LockSettingsService.java
index 121b7c8..31b8ef2 100644
--- a/services/core/java/com/android/server/locksettings/LockSettingsService.java
+++ b/services/core/java/com/android/server/locksettings/LockSettingsService.java
@@ -1156,18 +1156,21 @@
     @Override
     public void setBoolean(String key, boolean value, int userId) {
         checkWritePermission();
+        Objects.requireNonNull(key);
         mStorage.setBoolean(key, value, userId);
     }
 
     @Override
     public void setLong(String key, long value, int userId) {
         checkWritePermission();
+        Objects.requireNonNull(key);
         mStorage.setLong(key, value, userId);
     }
 
     @Override
     public void setString(String key, String value, int userId) {
         checkWritePermission();
+        Objects.requireNonNull(key);
         mStorage.setString(key, value, userId);
     }
 
diff --git a/services/tests/servicestests/src/com/android/server/locksettings/LockSettingsServiceTests.java b/services/tests/servicestests/src/com/android/server/locksettings/LockSettingsServiceTests.java
index 41e3a08..60a033f 100644
--- a/services/tests/servicestests/src/com/android/server/locksettings/LockSettingsServiceTests.java
+++ b/services/tests/servicestests/src/com/android/server/locksettings/LockSettingsServiceTests.java
@@ -423,6 +423,21 @@
         checkPasswordHistoryLength(userId, 3);
     }
 
+    @Test(expected=NullPointerException.class)
+    public void testSetBooleanRejectsNullKey() {
+        mService.setBoolean(null, false, 0);
+    }
+
+    @Test(expected=NullPointerException.class)
+    public void testSetLongRejectsNullKey() {
+        mService.setLong(null, 0, 0);
+    }
+
+    @Test(expected=NullPointerException.class)
+    public void testSetStringRejectsNullKey() {
+        mService.setString(null, "value", 0);
+    }
+
     private void checkPasswordHistoryLength(int userId, int expectedLen) {
         String history = mService.getString(LockPatternUtils.PASSWORD_HISTORY_KEY, "", userId);
         String[] hashes = TextUtils.split(history, LockPatternUtils.PASSWORD_HISTORY_DELIMITER);