diff --git a/scripts/mk_unix_dist.py b/scripts/mk_unix_dist.py
index 301782ec8..72a7ba15f 100644
--- a/scripts/mk_unix_dist.py
+++ b/scripts/mk_unix_dist.py
@@ -59,7 +59,7 @@ def display_help():
     print("  --dotnet-key=<file>           sign the .NET assembly with the private key in <file>.")
     print("  --arch=<arch>                 set architecture (to arm64) to force arm64 build")
     print("  --nojava                      do not include Java bindings in the binary distribution files.")
-    print("  -os=<os>                      set OS version.")
+    print("  --os=<os>                     set OS version.")
     print("  --nopython                    do not include Python bindings in the binary distribution files.")
     print("  --githash                     include git hash in the Zip file.")
     exit(0)
@@ -76,6 +76,7 @@ def parse_options():
                                                                    'nodotnet',
                                                                    'dotnet-key=',
                                                                    'arch=',
+                                                                   'os=',
                                                                    'githash',
                                                                    'nopython'
                                                                    ])