diff --git a/src/landlab/components/concentration_tracker/concentration_tracker_for_space.py b/src/landlab/components/concentration_tracker/concentration_tracker_for_space.py
index e6b10eb75..68e287e64 100644
--- a/src/landlab/components/concentration_tracker/concentration_tracker_for_space.py
+++ b/src/landlab/components/concentration_tracker/concentration_tracker_for_space.py
@@ -252,7 +252,7 @@ class ConcentrationTrackerForSpace(Component):
             "optional": False,
             "units": "m/yr",
             "mapping": "node",
-            "doc":  (
+            "doc": (
                 "Sediment erosion flux from bed to water column (depth eroded per"
                 " unit time)"
             ),