diff --git a/src/IDF/Plugin/SyncGit/Cron.php b/src/IDF/Plugin/SyncGit/Cron.php
index 6d136f4..ffff9d5 100644
--- a/src/IDF/Plugin/SyncGit/Cron.php
+++ b/src/IDF/Plugin/SyncGit/Cron.php
@@ -59,6 +59,16 @@ class IDF_Plugin_SyncGit_Cron
                 $out .= sprintf($template, $cmd, $key->login, $content)."\n";
             }
         }
+        $out = "# indefero start" . PHP_EOL . $out . "# indefero end" . PHP_EOL;
+        
+        // We update only the part of the file between IDF_START / IDF_END comment
+        $original_keys = file_get_contents($authorized_keys);
+        if (strstr($original_keys, "# indefero start") && strstr($original_keys, "# indefero end")) {
+            $out = preg_replace('/(#\sindefero\sstart).+(#\sindefero\send\s\s?)/isU', 
+                                $out, $original_keys);
+        } else {
+             $out .= $original_keys;   
+        }
         file_put_contents($authorized_keys, $out, LOCK_EX);
     }