diff --git a/docs/docs/api.xml b/docs/docs/api.xml
index 14bccd70b..55ab868a6 100644
--- a/docs/docs/api.xml
+++ b/docs/docs/api.xml
@@ -1168,8 +1168,8 @@
                   <a href="dlib/threads/thread_pool_extension.h.html">here</a>.  It is 
                   implemented such that no memory allocations occur after the thread pool
                   has been constructed (the future object also doesn't perform any memory allocations or contain any system
-                  resources such as mutex objects).
-
+                  resources such as mutex objects) so long as the user doesn't call
+                  any of the add_task_by_value() routines.
                </description> 
 
                <examples>