diff --git a/ci_build/Dockerfile b/ci_build/Dockerfile
index 6fbe4cf..bf2f426 100644
--- a/ci_build/Dockerfile
+++ b/ci_build/Dockerfile
@@ -1,38 +1,35 @@
-# Image for launching TensorFlow Haskell tests.
+# Image for launching TensorFlow Haskell tests.  Unlike the
+# development image in docker/Dockerfile, this one doesn't require
+# stack to be installed on the host.  This comes at the expense of
+# flexibility.
+
 FROM tensorflow/tensorflow:nightly-devel
-# gcr.io/tensorflow/tensorflow:latest-devel
 MAINTAINER TensorFlow authors <tensorflow-haskell@googlegroups.com>
 
+# The build context directory is the top of the tensorflow-haskell
+# tree.
+ADD . /tfhs
+WORKDIR /tfhs
+
 RUN \
     apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 575159689BEFB442 && \
-    echo 'deb http://download.fpcomplete.com/ubuntu trusty main'| tee /etc/apt/sources.list.d/fpco.list
-
-RUN apt-get update
-
-RUN apt-get install -y \
+    echo 'deb http://download.fpcomplete.com/ubuntu trusty main'| tee /etc/apt/sources.list.d/fpco.list && \
+    apt-get update && \
+    apt-get install -y \
         # Avoids /usr/bin/ld: cannot find -ltinfo
         libncurses5-dev \
         # Makes stack viable in the container
         libgmp-dev \
         libcurl3-dev \
-        stack
-
-# The build context directory is the top of the tensorflow-haskell
-# tree.
-ADD . /tfhs
-
-WORKDIR /tfhs
-
-RUN git submodule init && git submodule update
-
-# Installs protoc and the libraries.
-RUN \
-    cd third_party/tensorflow && \
-    tensorflow/tools/ci_build/builds/configured CPU && \
-    bazel build -c opt '@protobuf//:protoc' && \
-    install -s bazel-bin/external/protobuf/protoc /usr/local/bin && \
-    bazel build -c opt '//tensorflow:libtensorflow_c.so' && \
-    install bazel-bin/tensorflow/libtensorflow_c.so /usr/local/lib && \
-    ldconfig
-
-RUN stack setup && stack test --only-dependencies
+        stack && \
+    git submodule init && git submodule update && \
+    # Installs protoc and the libraries.
+    ( cd third_party/tensorflow && \
+      tensorflow/tools/ci_build/builds/configured CPU && \
+      bazel build -c opt '@protobuf//:protoc' && \
+      install -s bazel-bin/external/protobuf/protoc /usr/local/bin && \
+      bazel build -c opt '//tensorflow:libtensorflow_c.so' && \
+      install bazel-bin/tensorflow/libtensorflow_c.so /usr/local/lib && \
+      ldconfig ) && \
+    stack setup && \
+    stack test --only-dependencies