diff --git a/configure.ac b/configure.ac
index af7b87eb..1e83300b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -6,6 +6,8 @@ AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_LIBOBJ_DIR([portable])
 AC_CONFIG_HEADERS(include/config.h)
 
+AC_ARG_VAR(WIDL, [widl IDL compiler])
+
 dnl Check for progs
 AM_PROG_AR
 AC_PROG_CC