diff --git a/openstack_releases/gitutils.py b/openstack_releases/gitutils.py
index 2861545d92..197860face 100644
--- a/openstack_releases/gitutils.py
+++ b/openstack_releases/gitutils.py
@@ -26,7 +26,7 @@ CGIT_TEMPLATE = 'http://git.openstack.org/cgit/%s/commit/?id=%s'
 def find_modified_deliverable_files():
     "Return a list of files modified by the most recent commit."
     results = subprocess.check_output(
-        ['git', 'show', '--name-only', '--pretty=format:']
+        ['git', 'diff', '--name-only', '--pretty=format:', 'HEAD^']
     )
     filenames = [
         l.strip()
diff --git a/tox.ini b/tox.ini
index a414eaac5b..9011468b0c 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,6 +16,8 @@ deps = -r{toxinidir}/requirements.txt
 commands = validate-request {posargs}
 
 [testenv:list-changes]
+setenv =
+    PYTHONUNBUFFERED=1
 commands = list-changes {posargs}
 
 [testenv:pep8]