diff --git a/libsrc/include/nginterface.h b/libsrc/include/nginterface.h
index 2d76aa7c..4ded8217 100644
--- a/libsrc/include/nginterface.h
+++ b/libsrc/include/nginterface.h
@@ -12,6 +12,7 @@
 /**************************************************************************/
 
 #include "mydefs.hpp"
+#include <meshing/visual_interface.hpp>
 
 /*
   Application program interface to Netgen
@@ -451,15 +452,6 @@ extern "C" {
     return value is number of nodes
    */
   DLL_HEADER int Ng_GetElementClosureNodes (int dim, int elementnr, int nodeset, int * nodes);
-
-
-  struct Ng_Tcl_Interp;
-  typedef int (Ng_Tcl_CmdProc) (Ng_Tcl_Interp *interp, int argc, const char *argv[]);
-
-  DLL_HEADER void Ng_Tcl_CreateCommand (Ng_Tcl_Interp * interp, 
-                                        const char * cmdName, Ng_Tcl_CmdProc * proc);
-
-  void Ng_Tcl_SetResult (Ng_Tcl_Interp * interp, const char * result);
 }
 
 
diff --git a/libsrc/meshing/visual_interface.cpp b/libsrc/meshing/visual_interface.cpp
index 818bc215..cdb2a0ca 100644
--- a/libsrc/meshing/visual_interface.cpp
+++ b/libsrc/meshing/visual_interface.cpp
@@ -13,6 +13,9 @@ void Ng_Redraw (bool blocking) { if(Ptr_Ng_Redraw) Ptr_Ng_Redraw(blocking); }
 
 namespace netgen
 {
+    void (*Ptr_Ng_Tcl_SetResult)(Tcl_Interp *interp, char *result, const int freeProc) = nullptr;
+    void (*Ptr_Ng_Tcl_CreateCommand)(Tcl_Interp *interp,
+                                    const char *cmdName, Tcl_CmdProc *proc) = nullptr;
     void (*Ptr_Render)(bool) = nullptr;
     void (*Ptr_UpdateVisSurfaceMeshData)(int,
             shared_ptr<NgArray<Point<3>>>,
@@ -20,3 +23,4 @@ namespace netgen
             shared_ptr<NgArray<Point<2>>>
             ) = nullptr;
 } // namespace netgen
+
diff --git a/libsrc/meshing/visual_interface.hpp b/libsrc/meshing/visual_interface.hpp
index 120c7809..286cf82a 100644
--- a/libsrc/meshing/visual_interface.hpp
+++ b/libsrc/meshing/visual_interface.hpp
@@ -3,6 +3,7 @@
 
 #include <mystdlib.h>
 #include <meshing.hpp>
+#include <myadt.hpp>
 
 class Ng_SolutionData;
 
@@ -13,7 +14,25 @@ DLL_HEADER extern void (*Ptr_Ng_InitSolutionData) (Ng_SolutionData * soldata);
 DLL_HEADER extern void (*Ptr_Ng_SetSolutionData) (Ng_SolutionData * soldata);
 DLL_HEADER extern void (*Ptr_Ng_Redraw) (bool blocking);
 
+// Tcl wrapper functions
+class Tcl_Interp;
+typedef int (Tcl_CmdProc) (void * clientData, Tcl_Interp *interp,
+        int argc, const char *argv[]);
 namespace netgen {
+
+    inline constexpr int NG_TCL_VOLATILE = 1;
+    inline constexpr int NG_TCL_STATIC   = 0;
+    inline constexpr int NG_TCL_DYNAMIC  = 3;
+
+    inline constexpr int NG_TCL_OK       = 0;
+    inline constexpr int NG_TCL_ERROR    = 1;
+    inline constexpr int NG_TCL_RETURN   = 2;
+    inline constexpr int NG_TCL_BREAK    = 3;
+    inline constexpr int NG_TCL_CONTINUE = 4;
+    DLL_HEADER extern void (*Ptr_Ng_Tcl_SetResult)(Tcl_Interp *interp, char *result, const int freeProc);
+    DLL_HEADER extern void (*Ptr_Ng_Tcl_CreateCommand)(Tcl_Interp *interp,
+                                    const char *cmdName, Tcl_CmdProc *proc);
+
     DLL_HEADER extern void (*Ptr_Render)(bool);
     DLL_HEADER extern void (*Ptr_UpdateVisSurfaceMeshData)(int,
             shared_ptr<NgArray<Point<3>>>,
@@ -29,6 +48,17 @@ namespace netgen {
             ) {
         if(Ptr_UpdateVisSurfaceMeshData) Ptr_UpdateVisSurfaceMeshData(oldnl, locpointsptr, loclinesptr, plainpointsptr);
     }
+
+    inline void Ng_Tcl_SetResult(Tcl_Interp *interp, char *result, const int freeProc)
+    {
+        if(Ptr_Ng_Tcl_SetResult)
+            Ptr_Ng_Tcl_SetResult(interp, result, freeProc);
+    }
+    inline void Ng_Tcl_CreateCommand(Tcl_Interp *interp, const char *cmdName, Tcl_CmdProc *proc)
+    {
+        if(Ptr_Ng_Tcl_CreateCommand)
+            Ptr_Ng_Tcl_CreateCommand(interp, cmdName, proc);
+    }
 }
 
 #endif // VISUAL_INTERFACE_HPP_INCLUDED
diff --git a/ng/CMakeLists.txt b/ng/CMakeLists.txt
index 7571ec9e..58e34e2f 100644
--- a/ng/CMakeLists.txt
+++ b/ng/CMakeLists.txt
@@ -15,7 +15,7 @@ target_sources(nglib PRIVATE onetcl.cpp)
 
 if(USE_GUI)
     target_sources(nggui PRIVATE
-        gui.cpp ngpkg.cpp demoview.cpp parallelfunc.cpp ngtcl.cpp
+        gui.cpp ngpkg.cpp demoview.cpp parallelfunc.cpp
     )
 
     if(NOT BUILD_FOR_CONDA)
@@ -71,9 +71,5 @@ if(USE_GUI)
   endif()
 
   add_subdirectory(Togl2.1)
-  install(FILES
-    ngtcl.hpp
-    DESTINATION ${NG_INSTALL_DIR_INCLUDE} COMPONENT netgen_devel
-  )
 endif(USE_GUI)
 
diff --git a/ng/ngtcl.cpp b/ng/ngtcl.cpp
index 367228cb..125afa89 100644
--- a/ng/ngtcl.cpp
+++ b/ng/ngtcl.cpp
@@ -1,16 +1,9 @@
-#include "ngtcl.hpp"
+#include "../libsrc/meshing/visual_interface.hpp"
 
 #include <inctcl.hpp>
 
-namespace netgen
-{
-    void Ng_Tcl_SetResult(Tcl_Interp *interp, char *result, const int freeProc)
-    {
-      Tcl_SetResult(interp, result, (Tcl_FreeProc*)freeProc);
-    }
-
-    void Ng_Tcl_CreateCommand(Tcl_Interp *interp, const char *cmdName, Tcl_CmdProc *proc)
-    {
-      Tcl_CreateCommand(interp, cmdName, proc, nullptr, nullptr);
-    }
-}
+static bool dummy_init_pointers = [](){
+    Ptr_Ng_Tcl_SetResult = Tcl_SetResult;
+    Ptr_Ng_Tcl_CreateCommand = Tcl_CreateCommand;
+    return true;
+}();
diff --git a/ng/ngtcl.hpp b/ng/ngtcl.hpp
deleted file mode 100644
index a548cad9..00000000
--- a/ng/ngtcl.hpp
+++ /dev/null
@@ -1,30 +0,0 @@
-#ifndef FILE_NG_TCL_HPP
-#define FILE_NG_TCL_HPP
-
-#include <myadt.hpp>
-
-class Tcl_Interp;
-class Tcl_cmdProc;
-
-namespace netgen
-{
-    typedef int (Tcl_CmdProc) (void * clientData, Tcl_Interp *interp,
-            int argc, const char *argv[]);
-
-    inline constexpr int NG_TCL_VOLATILE = 1;
-    inline constexpr int NG_TCL_STATIC   = 0;
-    inline constexpr int NG_TCL_DYNAMIC  = 3;
-
-    inline constexpr int NG_TCL_OK       = 0;
-    inline constexpr int NG_TCL_ERROR    = 1;
-    inline constexpr int NG_TCL_RETURN   = 2;
-    inline constexpr int NG_TCL_BREAK    = 3;
-    inline constexpr int NG_TCL_CONTINUE = 4;
-
-    DLL_HEADER void Ng_Tcl_SetResult(Tcl_Interp *interp, char *result, const int freeProc);
-    DLL_HEADER void Ng_Tcl_CreateCommand(Tcl_Interp *interp,
-				const char *cmdName, Tcl_CmdProc *proc);
-
-}
-
-#endif // FILE_NG_TCL_HPP