diff --git a/mock_dbus_wrapper.h b/mock_dbus_wrapper.h
index 9c1f7c0..5d630a6 100644
--- a/mock_dbus_wrapper.h
+++ b/mock_dbus_wrapper.h
@@ -41,6 +41,10 @@
                                        const char* in2,
                                        const char* in3));
 
+  MOCK_METHOD3(ProxyAddSignal_1, void(DBusGProxy* proxy,
+                                      const char* signal_name,
+                                      GType type1));
+
   MOCK_METHOD4(ProxyAddSignal_2, void(DBusGProxy* proxy,
                                       const char* signal_name,
                                       GType type1,