diff --git a/u3/flatten_array.py b/u3/flatten_array.py
index 833c230..6f948c3 100644
--- a/u3/flatten_array.py
+++ b/u3/flatten_array.py
@@ -6,6 +6,7 @@ def flatten(inputs):
                 result.append(sub)
         else:
             if item is not None:
+                result.append(item)
     return result