diff --git a/package/x11r7/xproto_inputproto/xproto_inputproto.mk b/package/x11r7/xproto_inputproto/xproto_inputproto.mk
index 20169b5c46..5b3c63a588 100644
--- a/package/x11r7/xproto_inputproto/xproto_inputproto.mk
+++ b/package/x11r7/xproto_inputproto/xproto_inputproto.mk
@@ -11,6 +11,7 @@ XPROTO_INPUTPROTO_LICENSE = MIT
 XPROTO_INPUTPROTO_LICENSE_FILES = COPYING
 XPROTO_INPUTPROTO_INSTALL_STAGING = YES
 XPROTO_INPUTPROTO_INSTALL_TARGET = NO
+XPROTO_INPUTPROTO_CONF_ENV = ac_cv_path_ASCIIDOC=""
 
 $(eval $(autotools-package))
 $(eval $(host-autotools-package))