diff --git a/coreos-config/roles/compose_project/templates/matrix/docker-compose.yaml b/coreos-config/roles/compose_project/templates/matrix/docker-compose.yaml
index 2bff52a..6958ef2 100644
--- a/coreos-config/roles/compose_project/templates/matrix/docker-compose.yaml
+++ b/coreos-config/roles/compose_project/templates/matrix/docker-compose.yaml
@@ -15,6 +15,10 @@ services:
       - SYNAPSE_CONFIG_DIR=/config
       - SYNAPSE_CONFIG_PATH=/config/homeserver.yaml
       - TZ=Europe/Berlin
+    ulimits:
+      nofile:
+        soft: 10000
+        hard: 40000
     volumes:
       - synapse_data:/data
       - ./synapse-config:/config:ro,Z