diff --git a/src/event/Call.hxx b/src/event/Call.hxx
index 7a3011b1b..5663ef9e2 100644
--- a/src/event/Call.hxx
+++ b/src/event/Call.hxx
@@ -29,6 +29,8 @@ class EventLoop;
 /**
  * Call the given function in the context of the #EventLoop, and wait
  * for it to finish.
+ *
+ * Exceptions thrown by the given function will be rethrown.
  */
 void
 BlockingCall(EventLoop &loop, std::function<void()> &&f);