diff --git a/co_sim_io/c/co_sim_io_c.cpp b/co_sim_io/c/co_sim_io_c.cpp
index 6facfa56..39dd54ee 100644
--- a/co_sim_io/c/co_sim_io_c.cpp
+++ b/co_sim_io/c/co_sim_io_c.cpp
@@ -56,7 +56,7 @@ CoSimIO_Info CoSimIO_ImportData(
 CoSimIO_Info CoSimIO_ExportData(
     const CoSimIO_Info I_Info,
     const int I_Size,
-    const double** I_Data)
+    const double* I_Data)
 {
     using namespace CoSimIO::Internals;
     std::unique_ptr<DataContainer<double>> p_container(new DataContainerRawMemoryReadOnly<double>(I_Data, I_Size));
@@ -67,13 +67,14 @@ CoSimIO_Info CoSimIO_ImportMesh(
     const CoSimIO_Info I_Info,
     int* I_NumberOfNodes,
     int* I_NumberOfElements,
+    int* I_NumberOfElementConnectivities,
     double** I_NodalCoordinates,
     int** I_ElementConnectivities,
     int** I_ElementTypes)
 {
     using namespace CoSimIO::Internals;
     std::unique_ptr<DataContainer<double>> p_container_coords(new DataContainerRawMemory<double>(I_NodalCoordinates, *I_NumberOfNodes));
-    std::unique_ptr<DataContainer<int>> p_container_conn(new DataContainerRawMemory<int>(I_ElementConnectivities, *I_NumberOfElements)); // using "NumberOfElements" here is wrong! => has to be computed! Or sth like this ... (maybe even has to be passed...)
+    std::unique_ptr<DataContainer<int>> p_container_conn(new DataContainerRawMemory<int>(I_ElementConnectivities, *I_NumberOfElementConnectivities));
     std::unique_ptr<DataContainer<int>> p_container_types(new DataContainerRawMemory<int>(I_ElementTypes, *I_NumberOfElements));
     auto info = ConvertInfo(CoSimIO::ImportMesh(ConvertInfo(I_Info), *p_container_coords, *p_container_conn, *p_container_types));
     *I_NumberOfNodes = static_cast<int>(p_container_coords->size());
@@ -85,13 +86,14 @@ CoSimIO_Info CoSimIO_ExportMesh(
     const CoSimIO_Info I_Info,
     const int O_NumberOfNodes,
     const int O_NumberOfElements,
-    const double** O_NodalCoordinates,
-    const int** O_ElementConnectivities,
-    const int** O_ElementTypes)
+    const int O_NumberOfElementConnectivities,
+    const double* O_NodalCoordinates,
+    const int* O_ElementConnectivities,
+    const int* O_ElementTypes)
 {
     using namespace CoSimIO::Internals;
     std::unique_ptr<DataContainer<double>> p_container_coords(new DataContainerRawMemoryReadOnly<double>(O_NodalCoordinates, O_NumberOfNodes));
-    std::unique_ptr<DataContainer<int>> p_container_conn(new DataContainerRawMemoryReadOnly<int>(O_ElementConnectivities, O_NumberOfElements)); // using "NumberOfElements" here is wrong! => has to be computed! Or sth like this ... (maybe even has to be passed...)
+    std::unique_ptr<DataContainer<int>> p_container_conn(new DataContainerRawMemoryReadOnly<int>(O_ElementConnectivities, O_NumberOfElementConnectivities));
     std::unique_ptr<DataContainer<int>> p_container_types(new DataContainerRawMemoryReadOnly<int>(O_ElementTypes, O_NumberOfElements));
     return ConvertInfo(CoSimIO::ExportMesh(ConvertInfo(I_Info), *p_container_coords, *p_container_conn, *p_container_types));
 }
diff --git a/co_sim_io/c/co_sim_io_c.h b/co_sim_io/c/co_sim_io_c.h
index 8ce61982..1802fee0 100644
--- a/co_sim_io/c/co_sim_io_c.h
+++ b/co_sim_io/c/co_sim_io_c.h
@@ -30,29 +30,31 @@ CoSimIO_Info CoSimIO_Disconnect(
 
 CoSimIO_Info CoSimIO_ImportData(
     const CoSimIO_Info I_Info,
-    int* pSize,
-    double** ppData);
+    int* O_Size,
+    double** O_Data);
 
 CoSimIO_Info CoSimIO_ExportData(
-    const CoSimIO_Info* I_Info,
+    const CoSimIO_Info I_Info,
     const int I_Size,
-    const double** pData);
+    const double* I_Data);
 
 CoSimIO_Info CoSimIO_ImportMesh(
     const CoSimIO_Info I_Info,
-    int* pNumberOfNodes,
-    int* pNumberOfElements,
-    double** O_NodalCoordinates,
-    int** ppElementConnectivities,
-    int** ppElementTypes);
+    int* I_NumberOfNodes,
+    int* I_NumberOfElements,
+    int* I_NumberOfElementConnectivities,
+    double** I_NodalCoordinates,
+    int** I_ElementConnectivities,
+    int** I_ElementTypes);
 
 CoSimIO_Info CoSimIO_ExportMesh(
     const CoSimIO_Info I_Info,
-    const int NumberOfNodes,
-    const int NumberOfElements,
-    const double** pNodalCoordinates,
-    const int** pElementConnectivities,
-    const int** pElementTypes);
+    const int O_NumberOfNodes,
+    const int O_NumberOfElements,
+    const int O_NumberOfElementConnectivities,
+    const double* O_NodalCoordinates,
+    const int* O_ElementConnectivities,
+    const int* O_ElementTypes);
 
 
 CoSimIO_Info CoSimIO_ImportInfo(
diff --git a/co_sim_io/impl/data_container.hpp b/co_sim_io/impl/data_container.hpp
index 55d980de..e28c5a91 100644
--- a/co_sim_io/impl/data_container.hpp
+++ b/co_sim_io/impl/data_container.hpp
@@ -137,16 +137,16 @@ template<typename TDataType>
 class DataContainerRawMemoryReadOnly : public DataContainer<TDataType>
 {
 public:
-    explicit DataContainerRawMemoryReadOnly(const TDataType** ppData, const std::size_t Size)
-        : mppData(ppData), mSize(Size) {}
+    explicit DataContainerRawMemoryReadOnly(const TDataType* pData, const std::size_t Size)
+        : mpData(pData), mSize(Size) {}
 
     std::size_t size() const override {return mSize;};
     void resize(const std::size_t NewSize) override {CO_SIM_IO_ERROR << "Using non-const member of readonly object!" << std::endl;};
-    const TDataType* data() const override {return *mppData;}
+    const TDataType* data() const override {return mpData;}
     TDataType* data() override {CO_SIM_IO_ERROR << "Using non-const member of readonly object!" << std::endl; return nullptr;}
 
 private:
-    const TDataType** mppData;
+    const TDataType* mpData;
     const std::size_t mSize;
 };