diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 6266a39..fe0c17a 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -3661,7 +3661,12 @@
         // Tear down existing lockdown if profile was removed
         mLockdownEnabled = LockdownVpnTracker.isEnabled();
         if (mLockdownEnabled) {
-            final String profileName = new String(mKeyStore.get(Credentials.LOCKDOWN_VPN));
+            byte[] profileTag = mKeyStore.get(Credentials.LOCKDOWN_VPN);
+            if (profileTag == null) {
+                Slog.e(TAG, "Lockdown VPN configured but cannot be read from keystore");
+                return false;
+            }
+            String profileName = new String(profileTag);
             final VpnProfile profile = VpnProfile.decode(
                     profileName, mKeyStore.get(Credentials.VPN + profileName));
             if (profile == null) {