diff --git a/src/kits/app/Roster.cpp b/src/kits/app/Roster.cpp
index 0c40a9a158..f9a7789ec5 100644
--- a/src/kits/app/Roster.cpp
+++ b/src/kits/app/Roster.cpp
@@ -1740,7 +1740,8 @@ DBG(OUT("BRoster::xLaunchAppPrivate() done: %s (%lx)\n", strerror(error), error)
 	is notified, that it is active now, and all watchers are notified, too.
 
 	\param team The app's team ID.
-	\return \c true, if everything went fine, \c false, if an error occured.
+	\return \c true, if everything went fine, \c false, if an error occured
+			(the team ID is unknown or an communication error occured).
 */
 bool
 BRoster::UpdateActiveApp(team_id team) const