diff --git a/easytier/src/utils.rs b/easytier/src/utils.rs
index 9aba0cf..31e3a56 100644
--- a/easytier/src/utils.rs
+++ b/easytier/src/utils.rs
@@ -194,6 +194,7 @@ pub fn init_logger(
             .rotation(tracing_appender::rolling::Rotation::DAILY)
             .max_log_files(5)
             .filename_prefix(file_config.file.unwrap_or("easytier".to_string()))
+            .filename_suffix("log")
             .build(file_config.dir.unwrap_or("./".to_string()))
             .with_context(|| "failed to initialize rolling file appender")?;
         file_layer = Some(