diff --git a/setup.cfg b/setup.cfg
index c35d4a8495fbc3b6fc4086c05fa1b148c8867463..659b2061f2a7287abe7c405f454363626f5930e5 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -35,7 +35,8 @@ install_requires =
     zope.interface
     aniso8601
     privacypass
-    twisted
+    # Inherit our Twisted dependency from tahoe-lafs so we don't accidentally
+    # get the extras wrong here and break stuff.
     tahoe-lafs
     treq