diff --git a/gvafile/fileservertasks/tasks.py b/gvafile/fileservertasks/tasks.py
index cdb06cc..3f4473a 100644
--- a/gvafile/fileservertasks/tasks.py
+++ b/gvafile/fileservertasks/tasks.py
@@ -328,7 +328,7 @@ def set_file_ssh_authorized_keys(username, ssh_keys):
         try:
             subprocess.check_output([
                 SUDO_CMD, INSTALL_CMD, '-o', username, '-g', username,
-                'm', '0500', '-d', os.path.dirname(ssh_authorized_keys_file)],
+                '-m', '0500', '-d', os.path.dirname(ssh_authorized_keys_file)],
                 stderr=subprocess.STDOUT)
             subprocess.check_output([
                 SUDO_CMD, INSTALL_CMD, '-o', username, '-g', username,