diff --git a/doc/app_notes/inject_80211.md b/doc/app_notes/inject_80211.md
index d8cbfa5..7dbd53a 100644
--- a/doc/app_notes/inject_80211.md
+++ b/doc/app_notes/inject_80211.md
@@ -14,9 +14,15 @@ Luckily, the mac80211 Linux subsystem provides packet injection functionality an
 
 To this end, we have adapted a [packetspammer](https://github.com/gnychis/packetspammer) application originally written by Andy Green <andy@warmcat.com> and maintained by George Nychis <gnychis@gmail.com>.
 
-### inject_80211
+### Build inject_80211 on board
 Userspace program to inject 802.11 packets through mac80211 supported (softmac) wireless devices.
 
+Login/ssh to the board, then
+```
+cd openwifi/inject_80211
+make
+```
+
 ### Options
   ```
 -m/--hw_mode <hardware operation mode> (a,g,n)