Index: kitsh/buildsrc/kitsh-0.0/configure.ac
==================================================================
--- kitsh/buildsrc/kitsh-0.0/configure.ac
+++ kitsh/buildsrc/kitsh-0.0/configure.ac
@@ -20,8 +20,14 @@
 
 dnl Find the appropriate libraries to link to
 AC_SEARCH_LIBS(inflate, z zlib,, [ AC_MSG_WARN([Couldn't find inflate (normally in zlib)!]) ])
 AC_SEARCH_LIBS(acos, m,, [ AC_MSG_WARN([Couldn't find acos (normally in libm)!]) ])
 AC_SEARCH_LIBS(dlsym, dl,, [ AC_MSG_WARN([Couldn't find dlsym (normally in libdl)!]) ])
+
+dnl Determine if we have "Tcl_SetStartupScript" (8.6.x) or "TclSetStartupScriptPath" (8.4.x)
+SAVE_LIBS="${LIBS}"
+LIBS="${ARCHS} ${LIBS}"
+AC_CHECK_FUNCS(Tcl_SetStartupScript TclSetStartupScriptPath)
+LIBS="${SAVE_LIBS}"
 
 dnl Produce output
 AC_OUTPUT(Makefile)

Index: kitsh/buildsrc/kitsh-0.0/kitInit.c
==================================================================
--- kitsh/buildsrc/kitsh-0.0/kitInit.c
+++ kitsh/buildsrc/kitsh-0.0/kitInit.c
@@ -176,12 +176,20 @@
 #endif
 #endif
 
       /* messy because TclSetStartupScriptPath is called slightly too late */
     if (Tcl_Eval(interp, initScript) == TCL_OK) {
-        Tcl_Obj* path = TclGetStartupScriptPath();
+        Tcl_Obj* path;
+#ifdef HAVE_TCLSETSTARTUPSCRIPTPATH
+        path = TclGetStartupScriptPath();
+	TclSetStartupScriptPath(Tcl_GetObjResult(interp));
+#else
+#  ifdef HAVE_TCL_SETSTARTUPSCRIPT
+        path = Tcl_GetStartupScriptPath(NULL);
 	TclSetStartupScriptPath(Tcl_GetObjResult(interp));
+#  endif
+#endif
 	if (path == NULL)
 	  Tcl_Eval(interp, "incr argc -1; set argv [lrange $argv 1 end]");
     }
 
     Tcl_SetVar(interp, "errorInfo", "", TCL_GLOBAL_ONLY);