diff --git a/.env.sample b/.env.sample
index c3a7d5c..6a81ae3 100644
--- a/.env.sample
+++ b/.env.sample
@@ -76,6 +76,10 @@ ENCRYPTED_BY_DEFAULT=all
 #TRACK_PUPPETED_USER_IPS=true
 
 
+## Room complexity limit (prevents joining large remote rooms that cause DB bloat)
+## complexity ≈ state_events / 500. Default 100.0 blocks rooms with >50000 state events.
+#ROOM_COMPLEXITY_LIMIT=100.0
+
 ## Retention
 
 ALLOWED_LIFETIME_MAX=4w
diff --git a/abra.sh b/abra.sh
index 241ef5b..4f90829 100644
--- a/abra.sh
+++ b/abra.sh
@@ -1,6 +1,6 @@
 export DISCORD_BRIDGE_YAML_VERSION=v2
 export ENTRYPOINT_CONF_VERSION=v3
-export HOMESERVER_YAML_VERSION=v35
+export HOMESERVER_YAML_VERSION=v36
 export LOG_CONFIG_VERSION=v2
 export SHARED_SECRET_AUTH_VERSION=v2
 export SIGNAL_BRIDGE_YAML_VERSION=v6
diff --git a/compose.yml b/compose.yml
index a9209f6..0cc6bd7 100644
--- a/compose.yml
+++ b/compose.yml
@@ -90,6 +90,7 @@ services:
       - LOGIN_LIMIT_IP_BURST=${LOGIN_LIMIT_IP_BURST:-5}
       - LOGIN_LIMIT_ACCOUNT_PER_SECOND=${LOGIN_LIMIT_ACCOUNT_PER_SECOND:-0.003}
       - LOGIN_LIMIT_ACCOUNT_BURST=${LOGIN_LIMIT_ACCOUNT_BURST:-5}
+      - ROOM_COMPLEXITY_LIMIT=${ROOM_COMPLEXITY_LIMIT:-100.0}
       - WEB_CLIENT_LOCATION
     networks:
       - internal
diff --git a/homeserver.yaml.tmpl b/homeserver.yaml.tmpl
index 0fb7002..e51e2d7 100644
--- a/homeserver.yaml.tmpl
+++ b/homeserver.yaml.tmpl
@@ -69,7 +69,7 @@ admin_contact: 'mailto:{{ env "ADMIN_EMAIL" }}'
 # https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#limit_remote_rooms
 limit_remote_rooms:
   enabled: true
-  complexity: 200.0
+  complexity: {{ env "ROOM_COMPLEXITY_LIMIT" }}
 
 # https://matrix-org.github.io/synapse/latest/usage/configuration/config_documentation.html#max_avatar_size
 max_avatar_size: 10M