diff --git a/README.md b/README.md
index 586ac73..d0a4ac8 100644
--- a/README.md
+++ b/README.md
@@ -55,17 +55,17 @@ Variable | Usage
 
 
 ```shell
-echo "CATCHALL_MAILBOX_PASSWORD=$(openssl rand -base64 18)
+echo "CATCHALL_MAILBOX_PASSWORD='$(openssl rand -base64 18)'
 CLIENT_CERT_EMAIL=user@example.org
-CLIENT_CERT_PASSWORD=$(openssl rand -base64 18)
-CLIENT_CERT_USERNAME="John Doe"
-MYSQL_WEBDB_PASSWORD=$(openssl rand -base64 18)
+CLIENT_CERT_PASSWORD='$(openssl rand -base64 18)'
+CLIENT_CERT_USERNAME='John Doe'
+MYSQL_WEBDB_PASSWORD='$(openssl rand -base64 18)'
 MYSQL_WEBDB_USER=cacert_dev
-MYSQL_CATS_PASSWORD=$(openssl rand -base64 18)
+MYSQL_CATS_PASSWORD='$(openssl rand -base64 18)'
 MYSQL_CATS_USER=cats
-MYSQL_MGR_PASSWORD=$(openssl rand -base64 18)
+MYSQL_MGR_PASSWORD='$(openssl rand -base64 18)'
 MYSQL_MGR_USER=cacert_mgr
-MYSQL_ROOT_PASSWORD=$(openssl rand -base64 18)" > .env
+MYSQL_ROOT_PASSWORD='$(openssl rand -base64 18)'" | sed 's@/@_@g' > .env
 ./setup_test_ca.sh
 docker-compose up
 ```
diff --git a/signer.Dockerfile b/signer.Dockerfile
index fef29a6..6e4a0ab 100644
--- a/signer.Dockerfile
+++ b/signer.Dockerfile
@@ -1,10 +1,8 @@
-# should be etch or lenny but dockerhub doesn't have such old versions
-FROM debian:squeeze
+FROM debian:jessie
 
-RUN echo "deb http://archive.debian.org/debian squeeze main" > /etc/apt/sources.list ; \
-    apt-get -o=Acquire::AllowInsecureRepositories=true update \
+RUN apt-get update \
     && DEBIAN_FRONTEND=noninteractive \
-    apt-get -o=APT::Get::AllowUnauthenticated=true install -y --no-install-recommends \
+    apt-get install -y --no-install-recommends \
     gnupg \
     libdevice-serialport-perl \
     libdigest-sha-perl \