diff --git a/bridge/config/config.go b/bridge/config/config.go
index 71aed211..d6a0571b 100644
--- a/bridge/config/config.go
+++ b/bridge/config/config.go
@@ -185,7 +185,7 @@ func NewConfig(cfgfile string) *Config {
 	viper.SetConfigFile(cfgfile)
 	viper.SetEnvPrefix("matterbridge")
 	viper.AddConfigPath(".")
-	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_", "-", ""))
+	viper.SetEnvKeyReplacer(strings.NewReplacer(".", "_", "-", "_"))
 	viper.AutomaticEnv()
 	f, err := os.Open(cfgfile)
 	if err != nil {