diff --git a/Tethering/bpf_progs/test.c b/Tethering/bpf_progs/test.c
new file mode 100644
index 0000000..b5be33f
--- /dev/null
+++ b/Tethering/bpf_progs/test.c
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2021 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "bpf_helpers.h"
+#include "bpf_net_helpers.h"
+#include "netdbpf/bpf_shared.h"
+
+// Used only by TetheringPrivilegedTests, not by production code.
+DEFINE_BPF_MAP_GRW(tether_ingress_map, HASH, TetherIngressKey, TetherIngressValue, 16,
+                   AID_NETWORK_STACK)
+
+LICENSE("Apache 2.0");