diff --git a/swash/processing/read_swash.py b/swash/processing/read_swash.py
index cc24b2c..9d1906b 100644
--- a/swash/processing/read_swash.py
+++ b/swash/processing/read_swash.py
@@ -27,6 +27,7 @@ class ReadSwash:
             self._data[path.stem] = self.read_nohead(path).reshape(
                 (self._n_t, self._n_x)
             )[0, :]
+            return
         self._data[path.stem] = self.read_nohead(path).reshape(
             (self._n_t, self._n_x)
         )