diff --git a/README.md b/README.md
index a24cf2f..ce918b2 100644
--- a/README.md
+++ b/README.md
@@ -152,15 +152,6 @@ By default, FW_SUBDIR is initialised to the value of `os_prefix` in effect when
 the device was booted, so as to overwrite the "running" firmware. To explicitly
 install with no subdirectory (to install into /boot), use `FW_SUBDIR=/`.
 
-#### `BRANCH`
-
-By default, clones the firmware files from the master branch, else uses the files
-from the specified branch, eg:
-
-    sudo BRANCH=next rpi-update
-
-will use the 'next' branch.
-
 #### `PRUNE_MODULES`
 
 Allows you to delete unused module directories when doing an update. Set it equal to a non-zero value and it will remove all modules except the latest installed:
diff --git a/rpi-update b/rpi-update
index f94c71b..9d9260c 100755
--- a/rpi-update
+++ b/rpi-update
@@ -36,7 +36,6 @@ else
 	NOOBS_CHECK=${NOOBS_CHECK:-0}
 fi
 
-BRANCH=${BRANCH:-"master"}
 ROOT_PATH=${ROOT_PATH:-"/"}
 if command -v vcgencmd > /dev/null; then
 	CUR_FW_SUBDIR="/$(echo =$(vcgencmd get_config os_prefix) | cut -d'=' -f3)"
@@ -710,6 +709,11 @@ else
 	rm -f "${SELFUPDATE_SCRIPT}"
 fi
 
+if [ "${BRANCH:-"unset"}" != "unset" ]; then
+  echo 'Using the BRANCH variable is deprecated. Just use "rpi-update <branch>"'.
+  exit
+fi
+
 if [[ ! -d "${FW_PATH}" ]]; then
 	echo " !!! ${FW_PATH} doesn't exist - creating"
 	mkdir -p "${FW_PATH}"
@@ -731,14 +735,6 @@ command -v readelf >/dev/null 2>&1 || {
 	exit 1
 }
 
-if [[ "${FW_REV_IN}" == "" ]]; then
-	FW_REV_IN=${BRANCH}
-fi
-
-if [[ "${BOOTLOADER_REV_IN}" == "" ]]; then
-	BOOTLOADER_REV_IN=${BRANCH}
-fi
-
 ARTIFACT=""
 BUILD=""
 FW_REV=""