diff --git a/include/ACGL/OpenGL/Objects/LocationMappings.hh b/include/ACGL/OpenGL/Objects/LocationMappings.hh
index 0e80ad48f18a0dc6ecdda1ee99c3fb8df1d846f1..fc8d9f45f076188a4e070e211c27dcc6ec8bd06f 100644
--- a/include/ACGL/OpenGL/Objects/LocationMappings.hh
+++ b/include/ACGL/OpenGL/Objects/LocationMappings.hh
@@ -73,7 +73,7 @@ public:
     // ==================================================================================================== \/
 public:
     //! Tells whether a mapping for a given name exists
-    inline bool exists(const std::string& _name) const { mMappings.find(_name) != mMappings.end(); }
+    inline bool exists(const std::string& _name) const { return (mMappings.find(_name) != mMappings.end()); }
 
     // =================================================================================================== \/
     // ============================================================================================ FIELDS \/
diff --git a/include/ACGL/OpenGL/Objects/Query.hh b/include/ACGL/OpenGL/Objects/Query.hh
index 604b7ca54aeff609b1f68cf157bf523b37871381..a46b208d652793e205cdc2b767f14049748e36a7 100644
--- a/include/ACGL/OpenGL/Objects/Query.hh
+++ b/include/ACGL/OpenGL/Objects/Query.hh
@@ -132,7 +132,7 @@ public:
     TimerQuery() : AsynchronousQuery( GL_TIME_ELAPSED ) {}
 
     //! Mark the moment in the pipeline of which the time should get queried.
-    GLint saveTimestamp(void) {
+    void saveTimestamp(void) {
         glQueryCounter( mObjectName, GL_TIMESTAMP );
     }
 
diff --git a/src/ACGL/OpenGL/Controller/VertexBufferObjectControlFileOBJ.cc b/src/ACGL/OpenGL/Controller/VertexBufferObjectControlFileOBJ.cc
index e1c1bfe7f87a4890179d3c6a84b1fe378227d5c6..3cd2fd0177d2144460a2d98a90153f9fdabe05ec 100644
--- a/src/ACGL/OpenGL/Controller/VertexBufferObjectControlFileOBJ.cc
+++ b/src/ACGL/OpenGL/Controller/VertexBufferObjectControlFileOBJ.cc
@@ -43,7 +43,7 @@ SharedVertexBufferObject VertexBufferObjectControlFileOBJ::create(void)
 //    if(loadOBJ(vertexBuffer))
 //        return vertexBuffer;
 
-//    return SharedVertexBufferObject();
+    return SharedVertexBufferObject();
 }
 
 bool VertexBufferObjectControlFileOBJ::update(SharedVertexBufferObject& _vertexBuffer)
@@ -331,5 +331,5 @@ bool VertexBufferObjectControlFileOBJ::loadOBJ(SharedVertexBufferObject& _vertex
 //    }
 
 //    error() << "Failed to open file: " << getFullFilePath() << std::endl;
-//    return false;
+    return false;
 }
diff --git a/src/ACGL/OpenGL/Objects/ShaderProgram.cc b/src/ACGL/OpenGL/Objects/ShaderProgram.cc
index 8644f0ee3f49032cb7708e16136977076d3b3a4d..3821e1c3d640b325b62f3649a808923af181d47d 100644
--- a/src/ACGL/OpenGL/Objects/ShaderProgram.cc
+++ b/src/ACGL/OpenGL/Objects/ShaderProgram.cc
@@ -97,8 +97,8 @@ void ShaderProgram::setFragmentDataLocationsByFBO(ConstSharedFrameBufferObject _
     {
         // find out whether a fragment data location with a matching name exists in this shader
         GLint fragmentDataLocation = getFragmentDataLocation(fboAttachments[i].name);
-        if(fragmentDataLocation != -1  // fragment data location with that name exists?
-        && fragmentDataLocation != i)  // fragment data location with that name not already bound correctly?
+        if (   fragmentDataLocation != -1           // fragment data location with that name exists?
+            && fragmentDataLocation !=  (GLint) i)  // fragment data location with that name not already bound correctly?
         {
             bindFragmentDataLocation(fboAttachments[i].name, i);