diff --git a/cmd/github-mcp-server/main.go b/cmd/github-mcp-server/main.go
index cad002666..d7a3e34b4 100644
--- a/cmd/github-mcp-server/main.go
+++ b/cmd/github-mcp-server/main.go
@@ -92,6 +92,8 @@ func init() {
 func initConfig() {
 	// Initialize Viper configuration
 	viper.SetEnvPrefix("github")
+	// Replace hyphens with underscores in environment variable names
+	viper.SetEnvKeyReplacer(strings.NewReplacer("-", "_"))
 	viper.AutomaticEnv()
 
 }