diff --git a/rpi-update b/rpi-update
index f780efc..e899768 100755
--- a/rpi-update
+++ b/rpi-update
@@ -3,7 +3,7 @@
 set -o nounset
 set -o errexit
 
-REPO_URI="https://github.com/Hexxeh/rpi-firmware"
+REPO_URI=${REPO_URI:-"https://github.com/Hexxeh/rpi-firmware"}
 
 UPDATE_SELF=${UPDATE_SELF:-1}
 UPDATE_URI="https://github.com/Hexxeh/rpi-update/raw/master/rpi-update"