diff --git a/openmc/lib/cell.py b/openmc/lib/cell.py
index 5903a1075..c69d1e2a4 100644
--- a/openmc/lib/cell.py
+++ b/openmc/lib/cell.py
@@ -66,6 +66,11 @@ class Cell(_FortranObjectWithID):
 
     Parameters
     ----------
+    uid : int or None
+         Unique ID of the cell
+    new : bool
+         When `index` is None, this argument controls whether a new object is
+         created or a view to an existing object is returned.
     index : int
          Index in the `cells` array.
 
diff --git a/openmc/lib/material.py b/openmc/lib/material.py
index f3c794778..6f80abb5e 100644
--- a/openmc/lib/material.py
+++ b/openmc/lib/material.py
@@ -74,7 +74,7 @@ class Material(_FortranObjectWithID):
     Parameters
     ----------
     uid : int or None
-        Unique ID of the tally
+        Unique ID of the material
     new : bool
         When `index` is None, this argument controls whether a new object is
         created or a view to an existing object is returned.