diff --git a/docs/compile/build_howto_openwrt.txt b/docs/compile/build_howto_openwrt.txt
index 3a61c85..98999be 100644
--- a/docs/compile/build_howto_openwrt.txt
+++ b/docs/compile/build_howto_openwrt.txt
@@ -33,3 +33,4 @@ make package/{tpws,nfqws,mdig,ip2net}/compile
 
 ls -l bin/packages/*/base
 # take your ipk or apk from there
+# zlib-dev is not required