diff --git a/service-t/src/com/android/server/connectivity/mdns/MdnsSocket.java b/service-t/src/com/android/server/connectivity/mdns/MdnsSocket.java
index d690032..c51811b 100644
--- a/service-t/src/com/android/server/connectivity/mdns/MdnsSocket.java
+++ b/service-t/src/com/android/server/connectivity/mdns/MdnsSocket.java
@@ -128,9 +128,13 @@
      * cannot be determined, returns -1.
      */
     public int getInterfaceIndex() {
+        if (multicastSocket.isClosed()) {
+            sharedLog.e("Socket is closed");
+            return -1;
+        }
         try {
             return multicastSocket.getNetworkInterface().getIndex();
-        } catch (SocketException e) {
+        } catch (SocketException | NullPointerException e) {
             sharedLog.e("Failed to retrieve interface index for socket.", e);
             return -1;
         }