diff --git a/mod.nix b/mod.nix
index d7ce253..f073499 100644
--- a/mod.nix
+++ b/mod.nix
@@ -50,8 +50,8 @@ in
           '';
           keyScript = pkgs.writeScript "brownpaper-keyscript" ''
             DATADIR='${toString cfg.dataDir}'
-            [ -d "$DATADIR/keys" ] && mv "$DATADIR/keys" "$DATADIR/keys.bak"
-            [ -e "$DATADIR/keys" ] && rm "$DATADIR/keys"
+            ([ ! -s "$DATADIR/keys" ] && [ -d "$DATADIR/keys" ]) && mv "$DATADIR/keys" "$DATADIR/keys.bak"
+            [ -s "$DATADIR/keys" ] && rm "$DATADIR/keys"
             ln -s ${keyDir} "$DATADIR/keys"
           '';
         in