--- configure.ac
+++ configure.ac
@@ -60,7 +60,6 @@
 AC_PROG_LIBTOOL
 AC_PROG_MAKE_SET
 PKG_PROG_PKG_CONFIG
-AC_PROG_LEX
 AC_PROG_YACC
 AC_SYS_LARGEFILE
 XORG_PROG_RAWCPP
@@ -1139,6 +1138,7 @@
 		AC_MSG_ERROR([Xdmx build explicitly requested, but required
 		              modules not found.])
 	fi
+	AC_PROG_LEX
 	DMX_INCLUDES="$XEXT_INC $RENDER_INC $XTRAP_INC $RECORD_INC"
 	XDMX_LIBS="$FB_LIB $MI_LIB $XEXT_LIB $CONFIG_LIB $RENDER_LIB $XTRAP_LIB $RECORD_LIB $XI_LIB $XKB_LIB $XKB_STUB_LIB $MIEXT_DAMAGE_LIB $MIEXT_SHADOW_LIB $OS_LIB $CWRAP_LIB"
 	AC_SUBST([XDMX_LIBS])
@@ -1170,6 +1170,7 @@
 fi
 AM_CONDITIONAL([DMX_BUILD_LNX], [test "x$DMX_BUILD_LNX" = xyes])
 AM_CONDITIONAL([DMX_BUILD_USB], [test "x$DMX_BUILD_USB" = xyes])
+AC_SUBST([LEXLIB])
 
 
 dnl Xvfb DDX