diff --git a/FileIO/RapidXmlIO/RapidVtuInterface.cpp b/FileIO/RapidXmlIO/RapidVtuInterface.cpp
index 647a97cf8f64dd3be0a40e9af7c1b1e96191bb80..a4c472cb31aa10f7e30ed86d06acfad6561d167f 100644
--- a/FileIO/RapidXmlIO/RapidVtuInterface.cpp
+++ b/FileIO/RapidXmlIO/RapidVtuInterface.cpp
@@ -316,14 +316,14 @@ bool RapidVtuInterface::isVTKUnstructuredGrid(const rapidxml::xml_node<>* vtk_ro
 	return false;
 }
 
-char* RapidVtuInterface::uncompressData(const rapidxml::xml_node<>* node)
+unsigned char* RapidVtuInterface::uncompressData(const rapidxml::xml_node<>* node)
 {
 	rapidxml::xml_node<>* data_node = node->first_node("AppendedData");
 	char* compressed_data (NULL);
 	if (data_node)
 		compressed_data = data_node->value();
 
-	return compressed_data; //? return NULL; // Does here return compressed_data?
+	return NULL; // Does here return compressed_data?
 }
 
 
diff --git a/FileIO/RapidXmlIO/RapidVtuInterface.h b/FileIO/RapidXmlIO/RapidVtuInterface.h
index 1c95e616365a4cf40d9db284dd6429a37417a0d6..7a38b776fd82515652e962e01d1c824d0a33e6d3 100644
--- a/FileIO/RapidXmlIO/RapidVtuInterface.h
+++ b/FileIO/RapidXmlIO/RapidVtuInterface.h
@@ -77,7 +77,7 @@ private:
 	/// Construct an Element-object from the data given to the method and the data at the current stream position.
 	static MeshLib::Element* readElement(std::stringstream &iss, const std::vector<MeshLib::Node*> &nodes, unsigned material, unsigned type);
 
-	static char* uncompressData(const rapidxml::xml_node<>* node);
+	static unsigned char* uncompressData(const rapidxml::xml_node<>* node);
 
 	bool _use_compressor;
 };