--- a/taskcluster/ci/source-test/python-tests.yml
+++ b/taskcluster/ci/source-test/python-tests.yml
@@ -143,8 +143,28 @@ mozlint:
                 max-run-time: 3600
     run:
         using: mach
         mach: python-test --subsuite mozlint
     when:
         files-changed:
             - 'python/mozlint/**'
             - 'python/mach_commands.py'
+
+python3:
+    description: regression tests for python3 compatibility
+    platform: linux64/opt
+    treeherder:
+        symbol: py(3)
+        kind: test
+        tier: 2
+    worker-type: aws-provisioner-v1/gecko-t-linux-large
+    worker:
+        docker-image: {in-tree: "lint"}
+        max-run-time: 3600
+    run:
+        using: run-task
+        # this will evolve as we get closer and closer to python 3 compatibility. It may
+        # eventually be a mach command or shell script.
+        command: python3 -mcompileall python/
+    when:
+        files-changed:
+            - 'python/**/*.py'

--- a/taskcluster/docker/lint/system-setup.sh
+++ b/taskcluster/docker/lint/system-setup.sh
@@ -10,16 +10,18 @@ mkdir -p /setup
 cd /setup
 
 apt_packages=()
 apt_packages+=('curl')
 apt_packages+=('locales')
 apt_packages+=('git')
 apt_packages+=('python')
 apt_packages+=('python-pip')
+apt_packages+=('python3')
+apt_packages+=('python3-pip')
 apt_packages+=('sudo')
 apt_packages+=('wget')
 apt_packages+=('xz-utils')
 
 apt-get update
 apt-get install -y ${apt_packages[@]}
 
 # Without this we get spurious "LC_ALL: cannot change locale (en_US.UTF-8)" errors,