diff --git a/start.sh b/start.sh
index 0649af4..ce3f17d 100755
--- a/start.sh
+++ b/start.sh
@@ -69,6 +69,8 @@ if [[ -n "${CLOUDRON_LDAP_SERVER:-}" ]]; then
 
 else
     yq eval -i ".password_config.localdb_enabled=true" /app/data/configs/homeserver.yaml
+    # just setting enabled to false is not enough. see https://github.com/matrix-org/matrix-synapse-ldap3/issues/123
+    yq eval -i "del(.password_providers)" /app/data/configs/homeserver.yaml
 fi
 
 # turn (https://github.com/matrix-org/synapse/blob/master/docs/turn-howto.md#synapse-setup)