diff --git a/Tethering/src/com/android/networkstack/tethering/BpfMap.java b/Tethering/src/com/android/networkstack/tethering/BpfMap.java
index 78d212c..89caa8a 100644
--- a/Tethering/src/com/android/networkstack/tethering/BpfMap.java
+++ b/Tethering/src/com/android/networkstack/tethering/BpfMap.java
@@ -134,6 +134,11 @@
         return deleteMapEntry(mMapFd, key.writeToBytes());
     }
 
+    /** Returns {@code true} if this map contains no elements. */
+    public boolean isEmpty() throws ErrnoException {
+        return getFirstKey() == null;
+    }
+
     private K getNextKeyInternal(@Nullable K key) throws ErrnoException {
         final byte[] rawKey = getNextRawKey(
                 key == null ? null : key.writeToBytes());
diff --git a/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java b/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
index a0129b8..cceaa8c 100644
--- a/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
+++ b/Tethering/tests/privileged/src/com/android/networkstack/tethering/BpfMapTest.java
@@ -91,6 +91,7 @@
             }
         });
         assertNull(mTestMap.getFirstKey());
+        assertTrue(mTestMap.isEmpty());
     }
 
     private TetherDownstream6Key createTetherDownstream6Key(long iif, String address)
@@ -136,6 +137,18 @@
     }
 
     @Test
+    public void testIsEmpty() throws Exception {
+        assertNull(mTestMap.getFirstKey());
+        assertTrue(mTestMap.isEmpty());
+
+        mTestMap.insertEntry(mTestData.keyAt(0), mTestData.valueAt(0));
+        assertFalse(mTestMap.isEmpty());
+
+        mTestMap.deleteEntry((mTestData.keyAt(0)));
+        assertTrue(mTestMap.isEmpty());
+    }
+
+    @Test
     public void testGetFirstKey() throws Exception {
         // getFirstKey on an empty map returns null.
         assertFalse(mTestMap.containsKey(mTestData.keyAt(0)));