diff --git a/Dockerfile b/Dockerfile
index a70c9b5..8ebd9f4 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 ARG CONTEXT=prod
 
-FROM caddy:2.3.0-alpine as base
+FROM caddy:2.3.0-alpine AS base
 
 ## Setup
 ARG CONTEXT
@@ -30,17 +30,17 @@ CMD ["./command.sh"]
 
 # Development Image
 
-FROM base as dev
+FROM base AS dev
 
 ENV ENABLE_LOCAL_HTTPS=1
 
 # Testing Image
 
-FROM base as tests
+FROM base AS tests
 
 # Production Image
 
-FROM base as prod
+FROM base AS prod
 
 # Add appuser
 RUN adduser --system --no-create-home appuser && \
diff --git a/Makefile b/Makefile
index 28b2004..0b7910e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,14 +1,21 @@
-SERVICE=proxy
+override SERVICE=proxy
+
+# Build images for different contexts
 
 build-prod:
-	docker build ./ --tag "openslides-$(SERVICE)" --build-arg CONTEXT="prod" --target "prod"
+	docker build ./ $(ARGS) --tag "openslides-$(SERVICE)" --build-arg CONTEXT="prod" --target "prod"
 
 build-dev:
 	./make-localhost-cert.sh
-	docker build ./ --tag "openslides-$(SERVICE)-dev" --build-arg CONTEXT="dev" --target "dev"
+	docker build ./ $(ARGS) --tag "openslides-$(SERVICE)-dev" --build-arg CONTEXT="dev" --target "dev"
+
+build-tests:
+	docker build ./ $(ARGS) --tag "openslides-$(SERVICE)-tests" --build-arg CONTEXT="tests" --target "tests"
 
-build-test:
-	docker build ./ --tag "openslides-$(SERVICE)-tests" --build-arg CONTEXT="tests" --target "tests"
+# Tests
 
 run-tests:
-	echo "Proxy has no tests"
+	bash dev/run-tests.sh
+
+lint:
+	bash dev/run-lint.sh -l
diff --git a/dev/command.sh b/dev/command.sh
index ec45872..bcd5658 100644
--- a/dev/command.sh
+++ b/dev/command.sh
@@ -1,4 +1,4 @@
 #!/bin/sh
 
 # Same command for all contexts
-caddy run --config /etc/caddy/config.json
\ No newline at end of file
+caddy run --config /etc/caddy/config.json
diff --git a/dev/run-lint.sh b/dev/run-lint.sh
new file mode 100644
index 0000000..99dcf00
--- /dev/null
+++ b/dev/run-lint.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+echo "########################################################################"
+echo "####################### Proxy has no linters ###########################"
+echo "########################################################################"
diff --git a/dev/run-tests.sh b/dev/run-tests.sh
index 8c612be..43060af 100644
--- a/dev/run-tests.sh
+++ b/dev/run-tests.sh
@@ -1,5 +1,13 @@
 #!/bin/bash
 
+set -e
+
 echo "########################################################################"
 echo "###################### Proxy has no tests ##############################"
 echo "########################################################################"
+
+# Setup
+LOCAL_PWD=$(dirname "$0")
+
+# Linters
+bash "$LOCAL_PWD"/run-lint.sh