diff --git a/doc/RTD/source/Task/locks.rst b/doc/RTD/source/Task/locks.rst
index 5da48146d9c02cf12de3b47438b8979b6277530d..8dd40bc665c59c483d24fa600d2098c895088cf3 100644
--- a/doc/RTD/source/Task/locks.rst
+++ b/doc/RTD/source/Task/locks.rst
@@ -14,11 +14,11 @@ concurrently, even if the tasks have no dependencies between them.
 For this reason, each task locks the data it works on when it begins,
 and unlocks the data again once it's finished. Data here refers to the
 particle (gas, gravity, stars,...) content of a cell as well as of the
-hierarchy of cells in the tree at levels closer to the root that.  By
-default, it is assumed that the task is doing work on hydro
-particles. If your task requires other particle types, you will need
-to specify that in ``src/task.c``. Suppose you have implemented a task
-with type ``task_type_new`` that requires both stars and hydro
+hierarchy of cells in the tree at levels closer to the root than the
+cell itself.  By default, it is assumed that the task is doing work on
+hydro particles. If your task requires other particle types, you will
+need to specify that in ``src/task.c``. Suppose you have implemented a
+task with type ``task_type_new`` that requires both stars and hydro
 particles: ::