diff --git a/.travis.yml b/.travis.yml
index 4b4255e..6151249 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,5 +4,6 @@ language: bash
 env:
   - DOKKU_VERSION=master
   - DOKKU_VERSION=v0.4.14
+  - DOKKU_VERSION=v0.4.0
 before_install: make setup
 script: make test
diff --git a/functions b/functions
index 8568b37..e0fbc6a 100755
--- a/functions
+++ b/functions
@@ -2,7 +2,9 @@
 source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/config"
 set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
 source "$PLUGIN_AVAILABLE_PATH/config/functions"
-source "$PLUGIN_AVAILABLE_PATH/docker-options/functions"
+if [[ -f "$PLUGIN_AVAILABLE_PATH/docker-options/functions" ]]; then
+  source "$PLUGIN_AVAILABLE_PATH/docker-options/functions"
+fi
 
 docker_ports_options() {
   local PORTS=("$@")
@@ -167,9 +169,13 @@ service_link() {
     ALIAS=$(service_alternative_alias "$EXISTING_CONFIG")
   fi
 
-  # shellcheck disable=SC2034
-  local passed_phases=(build deploy run)
-  add_passed_docker_option passed_phases[@] "--link $SERVICE_NAME:$SERVICE_ALIAS"
+  if declare -f -F add_passed_docker_option > /dev/null; then
+    # shellcheck disable=SC2034
+    local passed_phases=(build deploy run)
+    add_passed_docker_option passed_phases[@] "--link $SERVICE_NAME:$SERVICE_ALIAS"
+  else
+    dokku docker-options:add "$APP" build,deploy,run "--link $SERVICE_NAME:$SERVICE_ALIAS"
+  fi
   config_set "$APP" "${ALIAS}_URL=$SERVICE_URL"
 }
 
@@ -328,9 +334,13 @@ service_unlink() {
   [[ -z ${LINK[*]} ]] && dokku_log_fail "Not linked to app $APP"
   remove_from_links_file "$SERVICE" "$APP"
 
-  # shellcheck disable=SC2034
-  local passed_phases=(build deploy run)
-  remove_passed_docker_option passed_phases[@] "--link $SERVICE_NAME:$SERVICE_ALIAS"
+  if declare -f -F add_passed_docker_option > /dev/null; then
+    # shellcheck disable=SC2034
+    local passed_phases=(build deploy run)
+    remove_passed_docker_option passed_phases[@] "--link $SERVICE_NAME:$SERVICE_ALIAS"
+  else
+    dokku docker-options:remove "$APP" build,deploy,run "--link $SERVICE_NAME:$SERVICE_ALIAS"
+  fi
   config_unset "$APP" "${LINK[*]}"
 }