diff --git a/pull_request_template.md b/pull_request_template.md
new file mode 100644
index 0000000..2a91a98
--- /dev/null
+++ b/pull_request_template.md
@@ -0,0 +1,5 @@
+Please ensure the following when opening a PR:
+- [ ] Added or updated tests
+- [ ] Updated documentation
+- [ ] Applied style guidelines
+- [ ] Considered generalizability beyond our own use case
diff --git a/requirements.txt b/requirements.txt
index e8d6ea7..ac48eae 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,3 @@
-requests
-six
+requests==2.18.4
+six==1.11.0
 tenacity==4.10.0
diff --git a/setup.py b/setup.py
index ce91191..6739a56 100644
--- a/setup.py
+++ b/setup.py
@@ -26,8 +26,8 @@
     license='BSD 3-clause "New" or "Revised" License',
     packages=['cromwell_tools'],
     install_requires=[
-        'requests',
-        'six'
+        'requests==2.18.4',
+        'six==1.11.0'
     ],
     scripts=['cromwell_tools/scripts/cromwell-tools'],
     include_package_data=True