diff --git a/components/resource/niffilemanager.cpp b/components/resource/niffilemanager.cpp
index ecb63db60..82768cc2c 100644
--- a/components/resource/niffilemanager.cpp
+++ b/components/resource/niffilemanager.cpp
@@ -1,5 +1,7 @@
 #include "niffilemanager.hpp"
 
+#include <osg/Object>
+
 #include <components/vfs/manager.hpp>
 
 #include "objectcache.hpp"
diff --git a/components/resource/objectcache.cpp b/components/resource/objectcache.cpp
index 17368f34f..a0a3cf3a5 100644
--- a/components/resource/objectcache.cpp
+++ b/components/resource/objectcache.cpp
@@ -13,6 +13,8 @@
 
 #include "objectcache.hpp"
 
+#include <osg/Object>
+
 namespace Resource
 {
 
diff --git a/components/resource/objectcache.hpp b/components/resource/objectcache.hpp
index b933933f3..79ebabd5b 100644
--- a/components/resource/objectcache.hpp
+++ b/components/resource/objectcache.hpp
@@ -17,13 +17,18 @@
 #ifndef OPENMW_COMPONENTS_RESOURCE_OBJECTCACHE
 #define OPENMW_COMPONENTS_RESOURCE_OBJECTCACHE
 
-#include <osg/Node>
-
-#include <osgDB/ReaderWriter>
-#include <osgDB/DatabaseRevisions>
+#include <osg/Referenced>
+#include <osg/ref_ptr>
 
+#include <string>
 #include <map>
 
+namespace osg
+{
+    class Object;
+    class State;
+}
+
 namespace Resource {
 
 class ObjectCache : public osg::Referenced