diff --git a/docs/source/design.rst b/docs/source/design.rst
index ae5410fd..c521512f 100644
--- a/docs/source/design.rst
+++ b/docs/source/design.rst
@@ -113,7 +113,7 @@ How Many Threads?
 ===================
 
 Since Gunicorn 19, a threads option can be used to process requests in multiple
-threads. Using threads assumes use of the sync worker. One benefit from threads
+threads. Using threads assumes use of the gthread worker. One benefit from threads
 is that requests can take longer than the worker timeout while notifying the
 master process that it is not frozen and should not be killed. Depending on the
 system, using multiple threads, multiple worker processes, or some mixture, may
diff --git a/docs/source/settings.rst b/docs/source/settings.rst
index 4a50f9c5..31f8486e 100644
--- a/docs/source/settings.rst
+++ b/docs/source/settings.rst
@@ -148,6 +148,8 @@ application's work load.
 
 If it is not defined, the default is ``1``.
 
+This setting only affects the Gthread worker type.
+
 .. _worker-connections:
 
 worker_connections
@@ -1214,4 +1216,3 @@ The variables are passed to the the PasteDeploy entrypoint. Example::
     $ gunicorn -b 127.0.0.1:8000 --paste development.ini --paste-global FOO=1 --paste-global BAR=2
 
 .. versionadded:: 19.7
-
diff --git a/gunicorn/config.py b/gunicorn/config.py
index 442f737c..67ffdd54 100644
--- a/gunicorn/config.py
+++ b/gunicorn/config.py
@@ -654,6 +654,8 @@ class WorkerThreads(Setting):
         application's work load.
 
         If it is not defined, the default is ``1``.
+
+        This setting only affects the Gthread worker type.
         """