diff --git a/Dockerfile b/Dockerfile
index 2c64c9d..858e51e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -2,12 +2,7 @@ FROM jcgruenhage/baseimage-alpine
 MAINTAINER Jan Christian Grünhage <jan.christian@gruenhage.xyz>
 
 ENV	UID=192 \
-	GID=192 \
-	STAGING=0 \
-	CHALLENGE="dns-01"
-
-# Set STAGING to false(0) by default, set to true(1) to use staging LE-Endpoint
-# Set CHALLENGE to "dns-01" (DNS Challenge) by default, set to "http-01" to use the HTTP Challenge
+	GID=192
 
 RUN apk update \
 	&& apk add --upgrade \
@@ -28,5 +23,3 @@ VOLUME /etc/dehydrated
 VOLUME /var/www/dehydrated
 VOLUME /certs
 
-# Execute the setup script
-RUN bash /etc/once/setup.sh
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..b7efaa8
--- /dev/null
+++ b/README.md
@@ -0,0 +1,10 @@
+#docker-dehydrated
+
+This is a docker container that wraps around [dehydrated](https://github.com/lukas2511/dehydrated).
+
+## Environment variables
+
+The following environment variables can be set to influence the container's behaviour:
+
+- $ENDPOINT which ACME-Endpoint you want to use, supported values: "staging", "production" (default).
+- $CHALLENGE what type of challenge should be used, supported values: "http-01" (default), "dns-01"
diff --git a/root/etc/once/setup.sh b/root/etc/once/setup.sh
deleted file mode 100644
index f17af00..0000000
--- a/root/etc/once/setup.sh
+++ /dev/null
@@ -1,23 +0,0 @@
-#!/bin/bash
-
-# Copy the example config file to the config location
-cp /dehydrated/docs/examples/config /etc/dehydrated/config
-
-# Use the staging endpoint?
-if [ $STAGING -ne 0 ]; then
-	sed -ie 's/#CA=.*$/CA="https:\/\/acme-staging.api.letsencrypt.org\/directory"/g' /etc/dehydrated/config
-	sed -ie 's/#CA_TERMS=.*$/CA_TERMS="https:\/\/acme-staging.api.letsencrypt.org\/terms"/g' /etc/dehydrated/config
-fi
-
-# Set the challenge-type
-case "$CHALLENGE" in
-	"http-01")
-		sed -ie 's/#CHALLENGETYPE=.*$/CHALLENGETYPE="http-01"/g' /etc/dehydrated/config
-	;;
-	"dns-01")
-		sed -ie 's/#CHALLENGETYPE=.*$/CHALLENGETYPE="dns-01"/g' /etc/dehydrated/config
-	;;
-	*)
-		echo "WARNING: Unknown Challenge type! Using default from dehydrated"
-	;;
-esac
diff --git a/root/etc/s6.d/setup/run b/root/etc/s6.d/setup/run
new file mode 100755
index 0000000..f5c0887
--- /dev/null
+++ b/root/etc/s6.d/setup/run
@@ -0,0 +1,55 @@
+#!/bin/bash
+s6-svc -O /etc/s6.d/dehydrated
+
+# Check if and which configuration file exists
+CONFIGFILE="none"
+for check_config in "/etc/dehydrated" "/usr/local/etc/dehydrated" "${PWD}" "${SCRIPTDIR}"; do
+	if [[ -f "${check_config}/config" ]]; then
+		CONFIGFILE="${check_config}/config"
+	fi
+done
+
+# At this point, no configuration file exists, so copy the example into /etc/dehydrated
+if [[ "$CONFIGFILE" == "none" ]]; then
+	cp /dehydrated/docs/examples/config /etc/dehydrated/config
+	CONFIGFILE="/etc/dehydrated/config"
+fi
+
+# Determine if the staging endpoint should be used
+case "$ENDPOINT" in
+	"staging")
+		# If CA=... is commented, uncomment and set it to staging, if it is set to production, set it to staging
+		sed -ie 's/#CA=.*$/CA="https:\/\/acme-staging.api.letsencrypt.org\/directory/g' $CONFIGFILE
+		sed -ie 's/CA=.+acme-v01\.api\..+$/CA="https:\/\/acme-staging.api.letsencrypt.org\/directory/g' $CONFIGFILE
+		# Same procedure for CA_TERMS=...
+		sed -ie 's/#CA_TERMS=.*$/CA_TERMS="https:\/\/acme-staging.api.letsencrypt.org\/terms"/g' $CONFIGFILE
+		sed -ie 's/CA_TERMS=.+acme-v01\.api\..+$/CA_TERMS="https:\/\/acme-staging.api.letsencrypt.org\/terms"/g' $CONFIGFILE
+	;;
+	"production")
+		# If CA=... is  commented, uncomment and set to production, if it was set to staging, set it to production
+		sed -ie 's/#CA=.*$/CA="https:\/\/acme-v01.api.letsencrypt.org\/directory"/g' $CONFIGFILE
+		sed -ie 's/CA=.+acme-staging\.api\..+$/https:\/\/acme-v01.api.letsencrypt.org\/directory/g' $CONFIGFILE
+		# Same thing for CA_TERMS=...
+		sed -ie 's/#CA_TERMS=.*$/CA_TERMS="https:\/\/acme-v01.api.letsencrypt.org\/terms"/g' $CONFIGFILE
+		sed -ie 's/CA_TERMS=.+acme-staging\.api\..+$/CA_TERMS="https:\/\/acme-v01.api.letsencrypt.org\/terms"/g' $CONFIGFILE
+	*)
+	;;
+esac
+
+# Determine which type of challenge should be used
+case "$CHALLENGE" in
+	"http-01")
+		# If we have a "fresh" config, uncomment the challengetype-line and set our value
+		sed -ie 's/#CHALLENGETYPE=.*$/CHALLENGETYPE="http-01"/g' $CONFIGFILE
+		# If a challengetype is already set, overwrite it
+		sed -ie 's/CHALLENGETYPE=.+$/CHALLENGETYPE="http-01"/g' $CONFIGFILE
+	;;
+	"dns-01")
+		# If we have the default config, uncomment the line and set our challengetype
+		sed -ie 's/#CHALLENGETYPE=.*$/CHALLENGETYPE="dns-01"/g' $CONFIGFILE
+		# If a challengetype was already set, overwrite it with the new value
+		sed -ie 's/CHALLENGETYPE=.+$/CHALLENGETYPE="dns-01"/g' $CONFIGFILE
+	;;
+	*)
+	;;
+esac