diff --git a/include/App/apptransport.h b/include/App/apptransport.h
index 2b81371..f7ad404 100644
--- a/include/App/apptransport.h
+++ b/include/App/apptransport.h
@@ -73,8 +73,13 @@ struct _AppTransportPluginDefinition
 	AppTransportPlugin * (*init)(AppTransportPluginHelper * helper,
 			AppTransportMode mode, char const * name);
 	void (*destroy)(AppTransportPlugin * transport);
-	int (*send)(AppTransportPlugin * transport, AppMessage * message);
+
+	/* ATM_CLIENT */
 	int (*client_send)(AppTransportPlugin * transport,
+			AppMessage * message);
+
+	/* ATM_SERVER */
+	int (*server_send)(AppTransportPlugin * transport,
 			AppTransportClient * client, AppMessage * message);
 };
 
diff --git a/src/apptransport.c b/src/apptransport.c
index e085f52..e3d6461 100644
--- a/src/apptransport.c
+++ b/src/apptransport.c
@@ -133,22 +133,7 @@ void apptransport_delete(AppTransport * transport)
 
 /* useful */
 /* apptransport_client_send */
-int apptransport_client_send(AppTransport * transport,
-		AppTransportClient * client, AppMessage * message)
-{
-	if(transport->mode != ATM_SERVER)
-		return -error_set_code(1, "%s",
-				"Only servers can reply to clients");
-	if(transport->definition->client_send == NULL)
-		return -error_set_code(1, "%s",
-				"This transport does not support replies");
-	return transport->definition->client_send(transport->tplugin, client,
-			message);
-}
-
-
-/* apptransport_send */
-int apptransport_send(AppTransport * transport, AppMessage * message,
+int apptransport_client_send(AppTransport * transport, AppMessage * message,
 		int acknowledge)
 {
 	if(transport->mode == ATM_CLIENT
@@ -156,7 +141,22 @@ int apptransport_send(AppTransport * transport, AppMessage * message,
 			&& acknowledge != 0)
 		/* FIXME will wrap around after 2^32-1 acknowledgements */
 		appmessage_set_id(message, ++transport->id);
-	return transport->definition->send(transport->tplugin, message);
+	return transport->definition->client_send(transport->tplugin, message);
+}
+
+
+/* apptransport_server_send */
+int apptransport_server_send(AppTransport * transport,
+		AppTransportClient * client, AppMessage * message)
+{
+	if(transport->mode != ATM_SERVER)
+		return -error_set_code(1, "%s",
+				"Only servers can reply to clients");
+	if(transport->definition->server_send == NULL)
+		return -error_set_code(1, "%s",
+				"This transport does not support replies");
+	return transport->definition->server_send(transport->tplugin, client,
+			message);
 }
 
 
@@ -226,7 +226,7 @@ static int _apptransport_helper_client_receive(AppTransport * transport,
 		/* XXX we can ignore errors */
 		if((message = appmessage_new_acknowledgement(id)) != NULL)
 		{
-			apptransport_client_send(transport, client, message);
+			apptransport_server_send(transport, client, message);
 			appmessage_delete(message);
 		}
 	return 0;
diff --git a/src/apptransport.h b/src/apptransport.h
index 4f09ab6..ed613e2 100644
--- a/src/apptransport.h
+++ b/src/apptransport.h
@@ -39,10 +39,12 @@ AppTransport * apptransport_new(AppTransportMode mode,
 void apptransport_delete(AppTransport * transport);
 
 /* useful */
-int apptransport_client_send(AppTransport * transport,
-		AppTransportClient * client, AppMessage * message);
-
-int apptransport_send(AppTransport * transport, AppMessage * message,
+/* ATM_CLIENT */
+int apptransport_client_send(AppTransport * transport, AppMessage * message,
 		int acknowledge);
 
+/* ATM_SERVER */
+int apptransport_server_send(AppTransport * transport,
+		AppTransportClient * client, AppMessage * message);
+
 #endif /* !LIBAPP_APPTRANSPORT_H */
diff --git a/tests/transport.c b/tests/transport.c
index cb8d371..0fe2e7c 100644
--- a/tests/transport.c
+++ b/tests/transport.c
@@ -207,7 +207,7 @@ static int _transport_callback_idle(void * data)
 #ifdef DEBUG
 	fprintf(stderr, "DEBUG: %s()\n", __func__);
 #endif
-	transport->plugind->send(transport->client, transport->message);
+	transport->plugind->client_send(transport->client, transport->message);
 	return 1;
 }