diff --git a/Makefile b/Makefile
index d1762f2..8824e31 100644
--- a/Makefile
+++ b/Makefile
@@ -10,6 +10,7 @@ SOTA_DIR = /var/sota
 
 DEVICE_FACTORY ?= ${FACTORY}
 DEVICE_TOKEN ?= ${AUTH_TOKEN}
+DEVICE_TAG ?= main
 
 .PHONY: config build
 
@@ -26,7 +27,7 @@ ${SOTA_DIR}:
 	mkdir -p ${SOTA_DIR}/compose-apps
 
 register: ${SOTA_DIR}
-	DEVICE_FACTORY=${DEVICE_FACTORY} lmp-device-register -T ${DEVICE_TOKEN} --start-daemon 0 -d ${SOTA_DIR} -t master
+	DEVICE_FACTORY=${DEVICE_FACTORY} lmp-device-register -T ${DEVICE_TOKEN} --start-daemon 0 -d ${SOTA_DIR} -t ${DEVICE_TAG}
 
 unregister:
 	@rm -rf ${SOTA_DIR}/sql.db
diff --git a/README.md b/README.md
index 8aec3e3..2e2d980 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,8 @@ Run `./dev-shell.sh`. The initial/first run may take some time as necessary cont
 
 ## Register/Unregister device
 Inside the development container, run `make register` or `make unregister` to register or unregister a device, respectively.
+Override the `DEVICE_TAG` environment variable if you need to register a device and set its tag to a non-default value (`main`).
+For example, `DEVICE_TAG=devel make register`.
 
 ## Build your SOTA client
 Run `make` to build your SOTA (Software Over-The-Air) client.
diff --git a/docker/.env.dev b/docker/.env.dev
index 0bfc5bb..e5ceadc 100644
--- a/docker/.env.dev
+++ b/docker/.env.dev
@@ -1,5 +1,6 @@
 FACTORY=$FACTORY
 AUTH_TOKEN=$USER_TOKEN
+DEVICE_TAG=main
 
 DEV_DIR=$PWD/.device
 SOTA_DIR=$DEV_DIR/sota
diff --git a/docker/docker-compose.yml b/docker/docker-compose.yml
index 67129ac..435794e 100644
--- a/docker/docker-compose.yml
+++ b/docker/docker-compose.yml
@@ -33,6 +33,7 @@ services:
       environment:
         - FACTORY=${FACTORY}
         - AUTH_TOKEN=${AUTH_TOKEN}
+        - DEVICE_TAG=${DEVICE_TAG}
         - DOCKER_HOST=unix:///var/run/docker/docker.sock
         - DOCKER_CONFIG=/usr/lib/docker
         - CXX=clang++