diff -ur brlcad-7.4.2.old/configure.ac brlcad-7.4.2/configure.ac
--- brlcad-7.4.2.old/configure.ac	2005-09-13 14:50:45.000000000 +0930
+++ brlcad-7.4.2/configure.ac	2005-09-13 14:52:18.000000000 +0930
@@ -1908,7 +1908,7 @@
 PRECPPFLAGS="$CPPFLAGS"
 if test "x$itcl_link_works" = "xyes" ; then
 	LIBS="$LIBS $LIBITCL $LIBTCL"
-	CPPFLAGS="$CPPFLAGS -Iinclude"
+	CPPFLAGS="$CPPFLAGS"
 fi
 AC_TRY_RUN([
 #include <itcl.h>