diff --git a/macro.c b/macro.c
index bc3a10e5..82ea66e7 100644
--- a/macro.c
+++ b/macro.c
@@ -271,8 +271,7 @@ static void KillExec(ClientData data)
 /*------------------------------------------------------------------------
   This is in the Tcl sources
 */
-extern int Tcl_ExecObjCmd(ClientData data, Tcl_Interp *interp,
-         int objc, Tcl_Obj *CONST objv[]);
+Tcl_CmdInfo cmd_info;
 /*-----------------------------------------------------------------------*/
 static int ProtectedExec(ClientData clientData, Tcl_Interp *interp,
 			 int objc, Tcl_Obj *CONST objv[])
@@ -281,7 +280,7 @@ static int ProtectedExec(ClientData clientData, Tcl_Interp *interp,
 
   if(objc < 2) 
   {
-    return Tcl_ExecObjCmd(clientData,interp,objc, objv);
+    return (cmd_info.objProc) (cmd_info.objClientData, interp, objc, objv);
   }
 
   test = Tcl_GetStringFromObj(objv[1],NULL);
@@ -289,7 +288,7 @@ static int ProtectedExec(ClientData clientData, Tcl_Interp *interp,
   {
     if(StringDictExists(allowedCommands,test))
     {
-      return Tcl_ExecObjCmd(clientData,interp,objc, objv);
+      return (cmd_info.objProc) (cmd_info.objClientData, interp, objc, objv);
     }
   }
   
@@ -336,11 +335,15 @@ extern int Nxinter_SafeInit(Tcl_Interp *pTcl); /* from Swig NeXus Tcl interface
       Tcl_CreateCommand(pInter,"unknown",(Tcl_CmdProc *)SicsUnknownProc,
                         pUnknown, UnknownKill);
 
-      /* delete dangers */
-      Tcl_DeleteCommand(pInter,"exit");
-      Tcl_DeleteCommand(pInter,"socket");
-      Tcl_DeleteCommand(pInter,"vwait");
-      Tcl_DeleteCommand(pInter,"exec"); 
+      /* hide dangers */
+      Tcl_HideCommand(pInter,"exit", "hidden_exit");
+      Tcl_HideCommand(pInter,"socket", "hidden_socket");
+      Tcl_HideCommand(pInter,"vwait", "hidden_vwait");
+      {
+        int retval = Tcl_GetCommandInfo(pInter, "exec", &cmd_info);
+        assert (retval != 0);
+      }
+      Tcl_HideCommand(pInter,"exec", "hidden_exec"); 
 
       /*
 	install protected exec command