diff --git a/scrapyd/Dockerfile b/scrapyd/Dockerfile
index 66d9eb6..42636f0 100644
--- a/scrapyd/Dockerfile
+++ b/scrapyd/Dockerfile
@@ -5,9 +5,6 @@
 FROM debian:jessie
 MAINTAINER kev <noreply@datageek.info>
 
-ADD ./packages.txt /etc/scrapyd/
-ADD ./requirements.txt /etc/scrapyd/
-
 RUN apt-get update \
     && apt-get install -y autoconf \
                           build-essential \
@@ -38,10 +35,7 @@ RUN apt-get update \
         && cd .. \
         && rm -rf libxslt \
     && curl -sSL https://bootstrap.pypa.io/get-pip.py | python \
-    && pip install scrapy==0.24.6 scrapyd==1.0.1 \
-    && xargs apt-get install -y < /etc/scrapyd/packages.txt \
-    && pip install -r /etc/scrapyd/requirements.txt \
-    && xargs apt-get remove -y < /etc/scrapyd/packages.txt \
+    && pip install scrapy==0.24.6 scrapyd==1.0.1 service_identity \
     && curl -sSL https://github.com/scrapy/scrapy/raw/master/extras/scrapy_bash_completion -o /etc/bash_completion.d/scrapy_bash_completion \
     && echo 'source /etc/bash_completion.d/scrapy_bash_completion' >> /root/.bashrc \
     && apt-get remove -y autoconf \
diff --git a/scrapyd/README.md b/scrapyd/README.md
index 27fb3fb..812aa43 100644
--- a/scrapyd/README.md
+++ b/scrapyd/README.md
@@ -5,9 +5,4 @@ Dockerfile for building an image that runs [scrapyd][1].
 
 Please use this image as base for your own project.
 
-You may edit these files:
-
-- `packages.txt` - dependencies for python requirements
-- `requirements.txt` - additional python packages to be installed
-
 [1]: https://github.com/scrapy/scrapyd
diff --git a/scrapyd/onbuild/Dockerfile b/scrapyd/onbuild/Dockerfile
new file mode 100644
index 0000000..75b81f6
--- /dev/null
+++ b/scrapyd/onbuild/Dockerfile
@@ -0,0 +1,15 @@
+#
+# Dockerfile for scrapyd-onbuild
+#
+
+FROM vimagick/scrapyd
+MAINTAINER kev <noreply@datageek.info>
+
+ONBUILD ADD ./*.txt /etc/scrapyd/
+ONBUILD RUN apt-get update \
+            && cd /etc/scrapyd \
+            && [[ -f packages.txt ]] && xargs -r apt-get install -y < packages.txt \
+            && [[ -f dependencies.txt ]] && xargs -r apt-get install -y < dependencies.txt \
+            && [[ -f requirements.txt ]] && pip install -r requirements.txt \
+            && [[ -f dependencies.txt ]] && xargs -r apt-get purge -y --auto-remove < dependencies.txt \
+            && rm -rf /usr/lib/apt/lists/*
diff --git a/scrapyd/onbuild/README.md b/scrapyd/onbuild/README.md
new file mode 100644
index 0000000..af97598
--- /dev/null
+++ b/scrapyd/onbuild/README.md
@@ -0,0 +1,14 @@
+scrapyd-onbuild
+===============
+
+Dockerfile for building an image that runs [scrapyd][1].  
+
+Please use this image as base for your own project.
+
+You may edit these files:
+
+- `packages.txt` - additional packages to be installed (via `apt-get install`)
+- `dependencies.txt` - dependencies for python requirements (via `apt-get install/purge`)
+- `requirements.txt` - additional python packages to be installed (via `pip install`)
+
+[1]: https://github.com/scrapy/scrapyd
diff --git a/scrapyd/onbuild/dependencies.txt b/scrapyd/onbuild/dependencies.txt
new file mode 100644
index 0000000..4c5d98c
--- /dev/null
+++ b/scrapyd/onbuild/dependencies.txt
@@ -0,0 +1,3 @@
+build-essential
+libpq-dev
+python-dev
diff --git a/scrapyd/onbuild/packages.txt b/scrapyd/onbuild/packages.txt
new file mode 100644
index 0000000..e69de29
diff --git a/scrapyd/onbuild/requirements.txt b/scrapyd/onbuild/requirements.txt
new file mode 100644
index 0000000..658130b
--- /dev/null
+++ b/scrapyd/onbuild/requirements.txt
@@ -0,0 +1 @@
+psycopg2
diff --git a/scrapyd/packages.txt b/scrapyd/packages.txt
deleted file mode 100644
index 6eb8678..0000000
--- a/scrapyd/packages.txt
+++ /dev/null
@@ -1 +0,0 @@
-libpq-dev
diff --git a/scrapyd/requirements.txt b/scrapyd/requirements.txt
deleted file mode 100644
index 1f87c1f..0000000
--- a/scrapyd/requirements.txt
+++ /dev/null
@@ -1,2 +0,0 @@
-psycopg2
-service_identity