diff --git a/boottools/btog.py b/boottools/btog.py
index 26a6721..0f1c463 100644
--- a/boottools/btog.py
+++ b/boottools/btog.py
@@ -229,6 +229,8 @@ def copy_og_files (builder, og_shared, ogrepo_ssh_key, ogclientmount, osdistrib,
     os.makedirs (f'{ogclientmount}/root/.ssh', exist_ok=True)
     shutil.copy (f'{ogrepo_ssh_key}/opengnsys',     f'{ogclientmount}/root/.ssh/id_ed25519')
     shutil.copy (f'{ogrepo_ssh_key}/opengnsys.pub', f'{ogclientmount}/root/.ssh/id_ed25519.pub')
+    os.chmod (f'{ogclientmount}/root/.ssh/id_ed25519',     0o0600)
+    os.chmod (f'{ogclientmount}/root/.ssh/id_ed25519.pub', 0o0600)
 
     subprocess.run (f'rsync -aH {builder}/includes/* {ogclientmount}/'              , shell=True)
     subprocess.run (f'rsync -aH {og_shared}/*        {ogclientmount}/opt/opengnsys/', shell=True)