diff --git a/docker/complement/conf/workers-shared-extra.yaml.j2 b/docker/complement/conf/workers-shared-extra.yaml.j2
index 9a74c617bc..a38cb73b3f 100644
--- a/docker/complement/conf/workers-shared-extra.yaml.j2
+++ b/docker/complement/conf/workers-shared-extra.yaml.j2
@@ -114,6 +114,8 @@ experimental_features:
   msc3983_appservice_otk_claims: true
   # Proxy key queries to exclusive ASes
   msc3984_appservice_key_query: true
+  # Pass through unsigned device data in /keys/query
+  msc4229_enabled: true
 
 server_notices:
   system_mxid_localpart: _server
diff --git a/scripts-dev/complement.sh b/scripts-dev/complement.sh
index b6dcb96e2c..30ee1b364d 100755
--- a/scripts-dev/complement.sh
+++ b/scripts-dev/complement.sh
@@ -225,6 +225,7 @@ test_packages=(
     ./tests/msc3902
     ./tests/msc3967
     ./tests/msc4140
+    ./tests/msc4229
 )
 
 # Enable dirty runs, so tests will reuse the same container where possible.