diff --git a/CHANGELOG.asciidoc b/CHANGELOG.asciidoc
index 897afabf7..4fdb41fd9 100644
--- a/CHANGELOG.asciidoc
+++ b/CHANGELOG.asciidoc
@@ -36,6 +36,12 @@ Major changes
   the entire browsing history.
 - Completely rewritten configuration system.
 
+Changed
+~~~~~~~
+
+- Upgrading qutebrowser with a version older than v0.4.0 still running now won't
+  work properly anymore.
+
 Fixes
 ~~~~~
 
diff --git a/tests/unit/misc/test_ipc.py b/tests/unit/misc/test_ipc.py
index d090f8be4..4a530a10b 100644
--- a/tests/unit/misc/test_ipc.py
+++ b/tests/unit/misc/test_ipc.py
@@ -26,7 +26,6 @@ import collections
 import logging
 import json
 import hashlib
-import subprocess
 from unittest import mock
 
 import pytest