diff --git a/README.md b/README.md
index 4b20cf4056a42a7f1d5a6b5a9edbd6ff8da623e8..ca21867346dd1a4af7805a9da8134f83b88861b5 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,7 @@ OPTIONS:
         --try-file <PATH>
             serve this file (server root relative) in place of missing files (useful for single page apps) [aliases:
             try-file-404]
-    -l, --upload_size_limit <upload_size_limit>    Upload file size limit (default 8 Mb) [default: 8000000]
+    -l, --upload-size-limit <upload_size_limit>    Upload file size limit [bytes] [default: 8000000]
 
 
 ```
diff --git a/src/main.rs b/src/main.rs
index 8a92499b94ce97a0cd085f61a85f8c70fea00850..0571392bd8f13bae53f53add177242aa8eb385d9 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -106,7 +106,7 @@ fn main() {
              .help("TLS/SSL certificate password"))
         .arg(clap::Arg::with_name("upload_size_limit")
              .short("l")
-             .long("upload_size_limit")
+             .long("upload-size-limit")
              .takes_value(true)
              .default_value("8000000")
              .validator(|s| {
@@ -114,7 +114,7 @@ fn main() {
                      Ok(_) => Ok(()),
                      Err(e) => Err(e.description().to_string())
                  }})
-             .help("Upload file size limit (default 8 Mb)"))
+             .help("Upload file size limit [bytes]"))
         .arg(clap::Arg::with_name("ip")
              .long("ip")
              .takes_value(true)