diff --git a/km3io/rootio.py b/km3io/rootio.py
index ccabe0d0b5f8f246e939b45484eea081c3db7023..a816ad1198dc23b7d23327b0c22848f2402f4cba 100644
--- a/km3io/rootio.py
+++ b/km3io/rootio.py
@@ -111,6 +111,10 @@ class EventReader:
         self.nested_branches = valid_nested_branches
         self._keys = keys
 
+    def __dir__(self):
+        """Tab completion in IPython"""
+        return list(self.keys()) + ["header"]
+
     def keys(self):
         """Returns all accessible branch keys, without the skipped ones."""
         return self._keys
@@ -320,6 +324,10 @@ class Branch:
         self._aliases = aliases
         self._index_chain = index_chain
 
+    def __dir__(self):
+        """Tab completion in IPython"""
+        return list(self.fields)
+
     def __getattr__(self, attr):
         if attr not in self._aliases:
             raise AttributeError(