diff --git a/m4/widl.m4 b/m4/widl.m4
index 2849356f..6d226064 100644
--- a/m4/widl.m4
+++ b/m4/widl.m4
@@ -5,7 +5,7 @@ AC_DEFUN([VKD3D_PROG_WIDL],
 
 AS_IF([test "x$WIDL" != "xno"],
 [AC_MSG_CHECKING([checking whether widl version >= $1.$2])
-vkd3d_widl_version=`$WIDL -V | $SED -E '/version/{s/.* version (.*)/\1/;q;}'`
+vkd3d_widl_version=`$WIDL -V 2>/dev/null | $SED -E '/version/{s/.* version (.*)/\1/;q;}'`
 
 AX_COMPARE_VERSION([$vkd3d_widl_version], [ge], [$1.$2],
                    [AC_MSG_RESULT([yes ($vkd3d_widl_version)])],