diff --git a/postpic/datareader/datareader.py b/postpic/datareader/datareader.py
index 68c8b6c..1cd6212 100644
--- a/postpic/datareader/datareader.py
+++ b/postpic/datareader/datareader.py
@@ -370,3 +370,6 @@ def __repr__(self):
 
     def times(self):
         return np.array([s.time() for s in self])
+
+    def timesteps(self):
+        return np.array([s.timestep() for s in self])