diff --git a/lib/base/object.hpp b/lib/base/object.hpp
index 06562cd45..36487d28a 100644
--- a/lib/base/object.hpp
+++ b/lib/base/object.hpp
@@ -117,8 +117,12 @@ private:
 	Object(const Object& other);
 	Object& operator=(const Object& rhs);
 
+#	ifndef _WIN32
+	intptr_t m_References;
+#	else /* _WIN32 */
 	uintptr_t m_References;
-	mutable boost::recursive_mutex m_Mutex;
+#	endif /* _WIN32 */
+	mutable uintptr_t m_Mutex;
 
 #ifdef I2_DEBUG
 #	ifndef _WIN32
@@ -145,11 +149,10 @@ inline void intrusive_ptr_add_ref(Object *object)
 
 inline void intrusive_ptr_release(Object *object)
 {
-	uintptr_t refs;
 #ifdef _WIN32
-	refs = InterlockedDecrement(&object->m_References);
+	uintptr_t refs = InterlockedDecrement(&object->m_References);
 #else /* _WIN32 */
-	refs = __sync_sub_and_fetch(&object->m_References, 1);
+	intptr_t refs = __sync_sub_and_fetch(&object->m_References, 1);
 #endif /* _WIN32 */
 
 	if (refs == 0)