ogra@styx:~/Devel/branches/snapcraft$ git diff
diff --git a/snapcraft/internal/meta.py b/snapcraft/internal/meta.py
index 6480583..d6c20ff 100644
--- a/snapcraft/internal/meta.py
+++ b/snapcraft/internal/meta.py
@@ -99,6 +99,9 @@ class _SnapPackaging:
 
     def write_snap_yaml(self):
         package_snap_path = os.path.join(self.meta_dir, 'snap.yaml')
+        if os.path.exists(package_snap_path):
+            snap_yaml = yaml.read(package_snap_path)
+            return snap_yaml
         snap_yaml = self._compose_snap_yaml()
 
         with open(package_snap_path, 'w') as f:
ogra@styx:~/Devel/branches/snapcraft$