diff --git a/changelog.d/19635.misc b/changelog.d/19635.misc
new file mode 100644
index 0000000000..5fcd8499c5
--- /dev/null
+++ b/changelog.d/19635.misc
@@ -0,0 +1 @@
+Allow clients to set their user's `m.fully_read` marker back to older events.
\ No newline at end of file