diff --git a/common.docker b/common.docker
index cb470a5..4bdf191 100644
--- a/common.docker
+++ b/common.docker
@@ -13,6 +13,7 @@ COPY \
   imagefiles/build-and-install-openssh.sh \
   imagefiles/install-cmake-binary.sh \
   imagefiles/install-liquidprompt-binary.sh \
+  imagefiles/install-python-packages.sh \
   imagefiles/utils.sh \
   /buildscripts/
 
@@ -32,18 +33,10 @@ RUN \
   fi; \
   /buildscripts/install-liquidprompt-binary.sh && \
   PYTHON=$([ -e /opt/python/cp35-cp35m/bin/python ] && echo "/opt/python/cp35-cp35m/bin/python" || echo "python") && \
+  /buildscripts/install-python-packages.sh -python ${PYTHON} && \
   /buildscripts/build-and-install-ninja.sh -python ${PYTHON} && \
-  rm -rf /buildscripts \
-  && \
-  ${PYTHON} -m pip install --ignore-installed conan
+  rm -rf /buildscripts
 
-RUN if [ -e /opt/python/cp35-cp35m/bin/python ]; then \
-    : nothing to do here since it is updated by manylinux-common/install-python-packages.sh ; \
-  else \
-    curl -# -LO https://bootstrap.pypa.io/get-pip.py && \
-    python get-pip.py --ignore-installed && \
-    rm get-pip.py || exit 1; \
-  fi
 
 RUN echo "root:root" | chpasswd
 WORKDIR /work
diff --git a/imagefiles/install-python-packages.sh b/imagefiles/install-python-packages.sh
new file mode 100755
index 0000000..1b44460
--- /dev/null
+++ b/imagefiles/install-python-packages.sh
@@ -0,0 +1,27 @@
+#!/bin/bash
+
+set -e
+set -o pipefail
+
+PYTHON=python
+while [ $# -gt 0 ]; do
+  case "$1" in
+    -python)
+      PYTHON=$2
+      shift
+      ;;
+    *)
+      echo "Usage: Usage: ${0##*/} [-python /path/to/bin/python]"
+      exit 1
+      ;;
+  esac
+  shift
+done
+
+cd /tmp
+
+curl -# -LO https://bootstrap.pypa.io/get-pip.py
+${PYTHON} get-pip.py --ignore-installed
+rm get-pip.py
+
+${PYTHON} -m pip install --ignore-installed conan