diff --git a/tests/test-bad-extension.t b/tests/test-bad-extension.t
--- a/tests/test-bad-extension.t
+++ b/tests/test-bad-extension.t
@@ -1,3 +1,4 @@
+#require no-chg
   $ filterlog () {
   >   sed -e 's!^[0-9/]* [0-9:]* ([0-9]*)>!YYYY/MM/DD HH:MM:SS (PID)>!'
   > }
diff --git a/tests/test-extension-timing.t b/tests/test-extension-timing.t
--- a/tests/test-extension-timing.t
+++ b/tests/test-extension-timing.t
@@ -1,3 +1,5 @@
+#require no-chg
+
 Test basic extension support
 
   $ cat > foobar.py <<EOF