diff --git a/include/openspace/engine/openspaceengine.h b/include/openspace/engine/openspaceengine.h
index 12e17d6a03..7a12cc6e2a 100644
--- a/include/openspace/engine/openspaceengine.h
+++ b/include/openspace/engine/openspaceengine.h
@@ -74,7 +74,6 @@ public:
         std::unique_ptr<WindowWrapper> windowWrapper,
         std::vector<std::string>& sgctArguments, bool& requestClose);
     static void destroy();
-    static bool isInitialized();
     static OpenSpaceEngine& ref();
 
     double runTime();
@@ -104,8 +103,7 @@ public:
     void toggleShutdownMode();
     
     void runPostInitializationScripts(const std::string& sceneDescription);
-    
-    
+
     // Guaranteed to return a valid pointer
     ConfigurationManager& configurationManager();
     LuaConsole& console();
@@ -137,34 +135,7 @@ public:
     };
     
     // Registers a callback for a specific CallbackOption
-    void registerModuleCallback(CallbackOption option, std::function<void()> function) {
-        switch (option) {
-            case CallbackOption::Initialize:
-                _moduleCallbacks.initialize.push_back(std::move(function));
-                break;
-            case CallbackOption::Deinitialize:
-                _moduleCallbacks.deinitialize.push_back(std::move(function));
-                break;
-            case CallbackOption::InitializeGL:
-                _moduleCallbacks.initializeGL.push_back(std::move(function));
-                break;
-            case CallbackOption::DeinitializeGL:
-                _moduleCallbacks.deinitializeGL.push_back(std::move(function));
-                break;
-            case CallbackOption::PreSync:
-                _moduleCallbacks.preSync.push_back(std::move(function));
-                break;
-            case CallbackOption::PostSyncPreDraw:
-                _moduleCallbacks.postSyncPreDraw.push_back(std::move(function));
-                break;
-            case CallbackOption::Render:
-                _moduleCallbacks.render.push_back(std::move(function));
-                break;
-            case CallbackOption::PostDraw:
-                _moduleCallbacks.postDraw.push_back(std::move(function));
-                break;
-        }
-    }
+    void registerModuleCallback(CallbackOption option, std::function<void()> function);
     
     // Registers a callback that is called when a new keyboard event is received
     void registerModuleKeyboardCallback(
@@ -192,10 +163,10 @@ public:
     static scripting::LuaLibrary luaLibrary();
 
 private:
-    OpenSpaceEngine(std::string programName, std::unique_ptr<WindowWrapper> windowWrapper);
+    OpenSpaceEngine(std::string programName,
+        std::unique_ptr<WindowWrapper> windowWrapper);
     ~OpenSpaceEngine() = default;
 
-    void clearAllWindows();
     void gatherCommandlineArguments();
     void loadFonts();
     void runPreInitializationScripts(const std::string& sceneDescription);
diff --git a/src/engine/openspaceengine.cpp b/src/engine/openspaceengine.cpp
index 9751553fe8..0f8b535d35 100644
--- a/src/engine/openspaceengine.cpp
+++ b/src/engine/openspaceengine.cpp
@@ -404,7 +404,7 @@ void OpenSpaceEngine::initialize() {
     // clear the screen so the user don't have to see old buffer contents from the
     // graphics card
     LDEBUG("Clearing all Windows");
-    clearAllWindows();
+    _windowWrapper->clearAllWindows(glm::vec4(0.f, 0.f, 0.f, 1.f));
 
     LDEBUG("Adding system components");
     // Detect and log OpenCL and OpenGL versions and available devices
@@ -616,14 +616,6 @@ void OpenSpaceEngine::writeDocumentation() {
     }
 }
 
-bool OpenSpaceEngine::isInitialized() {
-    return _engine != nullptr;
-}
-
-void OpenSpaceEngine::clearAllWindows() {
-    _windowWrapper->clearAllWindows(glm::vec4(0.f, 0.f, 0.f, 1.f));
-}
-
 void OpenSpaceEngine::gatherCommandlineArguments() {
     commandlineArgumentPlaceholders.configurationName = "";
     _commandlineParser->addCommand(std::make_unique<SingleCommand<std::string>>(
@@ -1104,7 +1096,40 @@ void OpenSpaceEngine::enableBarrier() {
 void OpenSpaceEngine::disableBarrier() {
     _windowWrapper->setBarrier(false);
 }
-    
+
+// Registers a callback for a specific CallbackOption
+void OpenSpaceEngine::registerModuleCallback(OpenSpaceEngine::CallbackOption option,
+                                             std::function<void()> function)
+{
+    switch (option) {
+        case CallbackOption::Initialize:
+            _moduleCallbacks.initialize.push_back(std::move(function));
+            break;
+        case CallbackOption::Deinitialize:
+            _moduleCallbacks.deinitialize.push_back(std::move(function));
+            break;
+        case CallbackOption::InitializeGL:
+            _moduleCallbacks.initializeGL.push_back(std::move(function));
+            break;
+        case CallbackOption::DeinitializeGL:
+            _moduleCallbacks.deinitializeGL.push_back(std::move(function));
+            break;
+        case CallbackOption::PreSync:
+            _moduleCallbacks.preSync.push_back(std::move(function));
+            break;
+        case CallbackOption::PostSyncPreDraw:
+            _moduleCallbacks.postSyncPreDraw.push_back(std::move(function));
+            break;
+        case CallbackOption::Render:
+            _moduleCallbacks.render.push_back(std::move(function));
+            break;
+        case CallbackOption::PostDraw:
+            _moduleCallbacks.postDraw.push_back(std::move(function));
+            break;
+        default:
+            ghoul_assert(false, "Missing case label");
+    }
+}
     
 void OpenSpaceEngine::registerModuleKeyboardCallback(
                                std::function<bool (Key, KeyModifier, KeyAction)> function)