diff --git a/alpine/Dockerfile b/alpine/Dockerfile
index eb2ef23..8c4973e 100644
--- a/alpine/Dockerfile
+++ b/alpine/Dockerfile
@@ -1,9 +1,11 @@
 FROM ruby:2.6-alpine
 
+ENV DOCKERIZE_VERSION v0.6.1
+
 RUN wget https://github.com/wrouesnel/p2cli/releases/download/r5/p2 -O /usr/local/bin/p2 \
         && chmod +x /usr/local/bin/p2
 
-RUN apk --no-cache add nodejs mariadb-client git bash libcap build-base mariadb-dev tzdata mariadb-connector-c \
+RUN apk --no-cache add nodejs mariadb-client git bash libcap build-base mariadb-dev tzdata mariadb-connector-c openssl \
         && git clone https://github.com/atech/postal.git /opt/postal \
 	&& rm -rf /var/lib/apt/lists/* \
 	&& gem install bundler \
@@ -16,6 +18,11 @@ RUN apk --no-cache add nodejs mariadb-client git bash libcap build-base mariadb-
 	&& apk del git mariadb-dev \
 	&& rm -rf /var/cache/apk/*
 
+## Install jwilder/dockerize
+RUN wget https://github.com/jwilder/dockerize/releases/download/$DOCKERIZE_VERSION/dockerize-alpine-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
+    && tar -C /usr/local/bin -xzvf dockerize-alpine-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
+    && rm dockerize-alpine-linux-amd64-$DOCKERIZE_VERSION.tar.gz
+
 ## Adjust permissions
 RUN setcap 'cap_net_bind_service=+ep' /usr/local/bin/ruby
 
diff --git a/alpine/src/docker-entrypoint.sh b/alpine/src/docker-entrypoint.sh
index c31cee2..d651426 100755
--- a/alpine/src/docker-entrypoint.sh
+++ b/alpine/src/docker-entrypoint.sh
@@ -13,14 +13,9 @@ if [ ! -f /opt/postal/config/postal.yml ] || [[ $(cat /opt/postal/config/postal.
   echo "  secret_key: {{secretkey}}" >> /opt/postal/config/postal.example.yml
   ## Generate config and keys
   /opt/postal/bin/postal initialize-config
-  ## Wait for MySQL to start up
-  echo "== Waiting for MySQL to start up =="
-  while ! mysqladmin ping -h mysql --silent; do
-    sleep 0.5
-  done
-  while ! mysql -hmysql -u root -p"$MYSQL_ROOT_PASSWORD" -e "use $MYSQL_DATABASE" 2> /dev/null; do
-    sleep 0.5
-  done
+  ## Wait for MySQL and RabbitMQ to start up
+  echo "== Waiting for MySQL and RabbitMQ to start up =="
+  dockerize -wait tcp://mysql:3306 -wait http://rabbitmq:5672/api/aliveness-test
   /opt/postal/bin/postal initialize
   /opt/postal/bin/postal make-user <<-EOF
 $POSTAL_EMAIL
@@ -29,14 +24,9 @@ $POSTAL_LNAME
 $POSTAL_PASSWORD
 EOF
 else
-  ## Wait for MySQL to start up
-  echo "== Waiting for MySQL to start up =="
-  while ! mysqladmin ping -h mysql --silent; do
-    sleep 0.5
-  done
-  while ! mysql -hmysql -u root -p"$MYSQL_ROOT_PASSWORD" -e "use $MYSQL_DATABASE" 2> /dev/null; do
-    sleep 0.5
-  done
+  ## Wait for MySQL and RabbitMQ to start up
+  echo "== Waiting for MySQL and RabbitMQ to start up =="
+  dockerize -wait tcp://mysql:3306 -wait http://rabbitmq:5672/api/aliveness-test
 fi
 ## Start Postal
 /opt/postal/bin/postal "$@"
diff --git a/ubuntu/Dockerfile b/ubuntu/Dockerfile
index 4975d16..37a63dd 100644
--- a/ubuntu/Dockerfile
+++ b/ubuntu/Dockerfile
@@ -1,4 +1,5 @@
 FROM ruby:2.6
+
 ENV DOCKERIZE_VERSION v0.6.1
 
 RUN curl -L https://github.com/wrouesnel/p2cli/releases/download/r5/p2 -o /usr/local/bin/p2 \
@@ -21,6 +22,7 @@ RUN apt-get -y update \
 	&& apt-get -y autoremove \
 	&& apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
 
+## Install jwilder/dockerize
 RUN wget https://github.com/jwilder/dockerize/releases/download/$DOCKERIZE_VERSION/dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
     && tar -C /usr/local/bin -xzvf dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
     && rm dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz