diff --git a/changelog.d/3909.misc b/changelog.d/3909.misc
new file mode 100644
index 0000000000000000000000000000000000000000..a8d72dacad5a8b423affe7f82abeed0120d713ba
--- /dev/null
+++ b/changelog.d/3909.misc
@@ -0,0 +1 @@
+Fix log format error in matrixfederationclient.py