diff --git a/libgui/acinclude.m4 b/libgui/acinclude.m4
index 1b5a83b..082a49c 100644
--- a/libgui/acinclude.m4
+++ b/libgui/acinclude.m4
@@ -8,8 +8,7 @@ dnl Note: you must use first use SC_LOAD_TCLCONFIG!
 AC_DEFUN([CY_AC_TCL_PRIVATE_HEADERS], [
   AC_MSG_CHECKING([for Tcl private headers])
   private_dir=""
-  for dir in "${TCL_INCLUDE_SPEC}/tcl-private" "${TCL_SRC_DIR}"; do
-    dir=`echo "${dir}/generic" | sed -e s/-I//`
+  for dir in "${TCL_INCLUDE_SPEC}" "${TCL_SRC_DIR}"; do
     if test -f "${dir}/tclInt.h"; then
       private_dir="${dir}"
       break