diff --git a/options.go b/options.go
index 7f474c8..7dcb12b 100644
--- a/options.go
+++ b/options.go
@@ -30,7 +30,7 @@ import (
 // or Config File
 type Options struct {
 	ProxyPrefix     string `flag:"proxy-prefix" cfg:"proxy_prefix" env:"OAUTH2_PROXY_PROXY_PREFIX"`
-	PingPath        string `flag:"ping-path" cfg:"ping-path" env:"OAUTH2_PROXY_PING_PATH"`
+	PingPath        string `flag:"ping-path" cfg:"ping_path" env:"OAUTH2_PROXY_PING_PATH"`
 	ProxyWebSockets bool   `flag:"proxy-websockets" cfg:"proxy_websockets" env:"OAUTH2_PROXY_PROXY_WEBSOCKETS"`
 	HTTPAddress     string `flag:"http-address" cfg:"http_address" env:"OAUTH2_PROXY_HTTP_ADDRESS"`
 	HTTPSAddress    string `flag:"https-address" cfg:"https_address" env:"OAUTH2_PROXY_HTTPS_ADDRESS"`