--- a/support/cltkVar.c	2024-06-04 20:18:35.940518270 +0200
+++ b/support/cltkVar.c	2024-06-04 20:18:49.456367424 +0200
@@ -75,7 +75,7 @@
         Tcl_Interp *interp, char *part1, char *part2, int flags));
  */
 static char * tracevar(ClientData clientdata, Tcl_Interp *interp,
-                char *name1, char *name2, int flags)
+                const char *name1, const char *name2, int flags)
      /* interp -> Interpreter containing variable. */
      /* name1  -> Name of variable. */
      /* name2  -> Second part of variable name. */