diff --git a/lib/fluent/plugin/out_splunk_hec.rb b/lib/fluent/plugin/out_splunk_hec.rb
index f218e3b..fcdd566 100644
--- a/lib/fluent/plugin/out_splunk_hec.rb
+++ b/lib/fluent/plugin/out_splunk_hec.rb
@@ -11,7 +11,7 @@ class SplunkHECOutput < ObjectBufferedOutput
 
     config_param :host, :string
     config_param :port, :integer
-    config_param :token, :string
+    config_param :token, :string, secret: true
 
     # for metadata
     config_param :default_host, :string, default: nil