diff --git a/ingen/src/libs/client/ModelEngineInterface.h b/ingen/src/libs/client/ModelEngineInterface.h
index 2bc5db14..42b95d00 100644
--- a/ingen/src/libs/client/ModelEngineInterface.h
+++ b/ingen/src/libs/client/ModelEngineInterface.h
@@ -31,14 +31,13 @@ namespace Client {
 class NodeModel;
 class PresetModel;
 class PatchModel;
-class ModelClientInterface;
 
 
 /** Model-based engine command interface.
  *
  * \ingroup IngenClient
  */
-class ModelEngineInterface
+class ModelEngineInterface : public virtual Shared::EngineInterface
 {
 public:
 	virtual ~ModelEngineInterface() {}
diff --git a/ingen/src/libs/client/OSCEngineSender.h b/ingen/src/libs/client/OSCEngineSender.h
index 184c0569..91e2d559 100644
--- a/ingen/src/libs/client/OSCEngineSender.h
+++ b/ingen/src/libs/client/OSCEngineSender.h
@@ -37,7 +37,7 @@ namespace Client {
  *
  * \ingroup IngenClient
  */
-class OSCEngineSender : public EngineInterface
+class OSCEngineSender : virtual public EngineInterface
 {
 public:
 	OSCEngineSender(const string& engine_url);
diff --git a/ingen/src/libs/client/PatchLibrarian.cpp b/ingen/src/libs/client/PatchLibrarian.cpp
index e09ac23c..86f3d407 100644
--- a/ingen/src/libs/client/PatchLibrarian.cpp
+++ b/ingen/src/libs/client/PatchLibrarian.cpp
@@ -25,7 +25,7 @@
 #include "ConnectionModel.h"
 #include "PortModel.h"
 #include "PresetModel.h"
-#include "OSCModelEngineInterface.h"
+#include "ModelEngineInterface.h"
 #include "PluginModel.h"
 #include "util/Path.h"
 #include <iostream>
diff --git a/ingen/src/libs/client/PatchLibrarian.h b/ingen/src/libs/client/PatchLibrarian.h
index 5c199974..a41d47e3 100644
--- a/ingen/src/libs/client/PatchLibrarian.h
+++ b/ingen/src/libs/client/PatchLibrarian.h
@@ -33,7 +33,7 @@ class PatchModel;
 class NodeModel;
 class ConnectionModel;
 class PresetModel;
-class OSCModelEngineInterface;
+class ModelEngineInterface;
 class ModelClientInterface;
 
 	
@@ -46,8 +46,8 @@ class PatchLibrarian
 public:
 	// FIXME: return booleans and set an errstr that can be checked or something?
 	
-	PatchLibrarian(OSCModelEngineInterface* osc_model_engine_interface)
-	: _patch_search_path("."), _engine(osc_model_engine_interface)
+	PatchLibrarian(ModelEngineInterface* _engine)
+	: _patch_search_path("."), _engine(_engine)
 	{
 		assert(_engine);
 	}
@@ -63,8 +63,8 @@ public:
 private:
 	string translate_load_path(const string& path);
 
-	string                         _patch_search_path;
-	OSCModelEngineInterface* const _engine;
+	string                      _patch_search_path;
+	ModelEngineInterface* const _engine;
 
 	/// Translations of paths from the loading file to actual paths (for deprecated patches)
 	std::map<string, string> _load_path_translations;