diff --git a/{{cookiecutter.repo_name}}/runtime.txt b/{{cookiecutter.repo_name}}/runtime.txt
new file mode 100644
index 000000000..e75f26b02
--- /dev/null
+++ b/{{cookiecutter.repo_name}}/runtime.txt
@@ -0,0 +1,3 @@
+{% if cookiecutter.use_python2= 'n' -%}
+FROM python:3.4
+{% else %}