diff --git a/dhcp_proxy_interface.h b/dhcp_proxy_interface.h
new file mode 100644
index 0000000..f9ba5bd
--- /dev/null
+++ b/dhcp_proxy_interface.h
@@ -0,0 +1,23 @@
+// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SHILL_DHCP_PROXY_INTERFACE_
+#define SHILL_DHCP_PROXY_INTERFACE_
+
+namespace shill {
+
+// These are the functions that a DHCP proxy and listener must support.
+class DHCPProxyInterface {
+ public:
+  virtual ~DHCPProxyInterface() {}
+};
+
+class DHCPListenerInterface {
+ public:
+  virtual ~DHCPListenerInterface() {}
+};
+
+}  // namespace shill
+
+#endif  // SHILL_DHCP_PROXY_INTERFACE_