diff --git a/openmc/deplete/stepresult.py b/openmc/deplete/stepresult.py
index d289382ca..dc205774f 100644
--- a/openmc/deplete/stepresult.py
+++ b/openmc/deplete/stepresult.py
@@ -57,6 +57,8 @@ class StepResult:
     proc_time : int
         Average time spent depleting a material across all
         materials and processes
+    keff_search_root : float
+        The root returned by the keff search control.
 
     """
     def __init__(self):