diff --git a/spec/acceptance/docker-compose.yml b/spec/acceptance/docker-compose.yml
index edfd915..fe5e785 100644
--- a/spec/acceptance/docker-compose.yml
+++ b/spec/acceptance/docker-compose.yml
@@ -30,7 +30,7 @@ services:
       - "${DIR}/spec/acceptance/git-server/keys:/git-server/keys:ro"
   ldap-server:
     entrypoint: /acceptance/ldap-server/run-server.sh
-    image: osixia/openldap:1.2.2
+    image: osixia/openldap:1.2.4
     networks:
       ldap-network:
         aliases:
diff --git a/spec/acceptance/ldap-server/env/default.startup.yaml b/spec/acceptance/ldap-server/env/default.startup.yaml
index ace4399..8458069 100644
--- a/spec/acceptance/ldap-server/env/default.startup.yaml
+++ b/spec/acceptance/ldap-server/env/default.startup.yaml
@@ -28,6 +28,7 @@ LDAP_TLS: true
 LDAP_TLS_CRT_FILENAME: ldap.crt
 LDAP_TLS_KEY_FILENAME: ldap.key
 LDAP_TLS_CA_CRT_FILENAME: ca.crt
+LDAP_TLS_DH_PARAM_FILENAME: dhparam.pem
 
 LDAP_TLS_ENFORCE: true
 LDAP_TLS_CIPHER_SUITE: SECURE256:+SECURE128:-VERS-TLS-ALL:+VERS-TLS1.2:-RSA:-DHE-DSS:-CAMELLIA-128-CBC:-CAMELLIA-256-CBC