diff --git a/tests/docker/docker.py b/tests/docker/docker.py
index 96d906e5be..76750c46d0 100755
--- a/tests/docker/docker.py
+++ b/tests/docker/docker.py
@@ -221,6 +221,18 @@ class BuildCommand(SubCommand):
             # Create a docker context directory for the build
             docker_dir = tempfile.mkdtemp(prefix="docker_build")
 
+            # Is there a .pre file to run in the build context?
+            docker_pre = os.path.splitext(args.dockerfile)[0]+".pre"
+            if os.path.exists(docker_pre):
+                rc = subprocess.call(os.path.realpath(docker_pre),
+                                     cwd=docker_dir)
+                if rc == 3:
+                    print "Skip"
+                    return 0
+                elif rc != 0:
+                    print "%s exited with code %d" % (docker_pre, rc)
+                    return 1
+
             # Do we include a extra binary?
             if args.include_executable:
                 _copy_binary_with_libs(args.include_executable,