diff --git a/buildkite/install-python36.sh b/buildkite/install-python36.sh
index f65c5ff..3c7e74a 100755
--- a/buildkite/install-python36.sh
+++ b/buildkite/install-python36.sh
@@ -14,10 +14,42 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-add-apt-repository -y "ppa:deadsnakes/ppa"
-apt-get -qqy update > /dev/null
-apt-get -qqy install python3.6 python3.6-dev python3.6-venv > /dev/null
-python3.6 -m ensurepip
+# add-apt-repository -y "ppa:deadsnakes/ppa"
+# apt-get -qqy update > /dev/null
+# apt-get -qqy install python3.6 python3.6-dev python3.6-venv > /dev/null
+# python3.6 -m ensurepip
+# rm -f /usr/local/bin/pip3
+# apt-get -qqy install python3-pip
+# pip3.6 install requests pyyaml
+# pip3.6 install --pre github3.py
 
-pip3.6 install requests pyyaml
+apt-get -qqy install zlib1g-dev libssl-dev
+
+PYTHON_VERSION="3.6.4"
+
+mkdir -p /usr/local/src
+pushd /usr/local/src
+
+curl -O "https://www.python.org/ftp/python/${PYTHON_VERSION}/Python-${PYTHON_VERSION}.tar.xz"
+tar xvfJ "Python-${PYTHON_VERSION}.tar.xz"
+rm -f "Python-${PYTHON_VERSION}.tar.xz"
+cd "Python-${PYTHON_VERSION}"
+
+# Enable the 'ssl' module.
+cat >> Modules/Setup.dist <<'EOF'
+_ssl _ssl.c \
+       -DUSE_SSL -I/usr/include -I/usr/include/openssl \
+       -L/usr/lib -lssl -lcrypto
+EOF
+
+echo "Compiling Python ${PYTHON_VERSION} ..."
+./configure --enable-ipv6
+make -s -j8 all > /dev/null
+echo "Installing Python ${PYTHON_VERSION} ..."
+make -s altinstall > /dev/null
+
+pip3.6 install requests uritemplate pyyaml
 pip3.6 install --pre github3.py
+
+popd
+rm -rf "/usr/local/src/Python-${PYTHON_VERSION}"
diff --git a/buildkite/setup-ubuntu.sh b/buildkite/setup-ubuntu.sh
index 9bbca14..a07b1a4 100755
--- a/buildkite/setup-ubuntu.sh
+++ b/buildkite/setup-ubuntu.sh
@@ -33,8 +33,14 @@
   git
   python
   python-dev
+  python-mock
+  python-numpy
+  python-pip
   python3
   python3-dev
+  python3-mock
+  python3-numpy
+  python3-pip
   realpath
   unzip
   wget
@@ -53,10 +59,6 @@
 
   # Dependencies for TensorFlow.
   libcurl3-dev
-  python-mock
-  python-numpy
-  python3-mock
-  python3-numpy
   swig
 )
 apt-get -qqy install "${packages[@]}" > /dev/null