diff --git a/changelog.d/11270.misc b/changelog.d/11270.misc
new file mode 100644
index 000000000000..e2181b9b2a79
--- /dev/null
+++ b/changelog.d/11270.misc
@@ -0,0 +1 @@
+Blacklist new SyTest that checks that key uploads are valid pending the validation being implemented in Synapse.
diff --git a/sytest-blacklist b/sytest-blacklist
index 65bf1774e353..57e603a4a605 100644
--- a/sytest-blacklist
+++ b/sytest-blacklist
@@ -32,3 +32,6 @@ We can't peek into rooms with invited history_visibility
 We can't peek into rooms with joined history_visibility
 Local users can peek by room alias
 Peeked rooms only turn up in the sync for the device who peeked them
+
+# Validation needs to be added to Synapse: #10554
+Rejects invalid device keys