diff --git a/Dockerfile b/Dockerfile
index 8c4cd0f54402612d2e0b8e513c31ec10055685d1..3d899f2404bdab92211850f3a97feb915b3485a8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.6
+FROM python:3.5
 MAINTAINER Paulus Schoutsen <Paulus@PaulusSchoutsen.nl>
 
 # Uncomment any of the following lines to disable the installation.
diff --git a/virtualization/Docker/Dockerfile.dev b/virtualization/Docker/Dockerfile.dev
index 2f40ea5f409a5bb24282f69b594acd0381355b6a..58d99285bc91dfb90510ddda4c48bb9e41e5964d 100644
--- a/virtualization/Docker/Dockerfile.dev
+++ b/virtualization/Docker/Dockerfile.dev
@@ -2,7 +2,7 @@
 # Based on the production Dockerfile, but with development additions.
 # Keep this file as close as possible to the production Dockerfile, so the environments match.
 
-FROM python:3.6
+FROM python:3.5
 MAINTAINER Paulus Schoutsen <Paulus@PaulusSchoutsen.nl>
 
 # Uncomment any of the following lines to disable the installation.