diff --git a/modules/juce_events/broadcasters/juce_AsyncUpdater.h b/modules/juce_events/broadcasters/juce_AsyncUpdater.h
index 6b207a87c5..3b61f21088 100644
--- a/modules/juce_events/broadcasters/juce_AsyncUpdater.h
+++ b/modules/juce_events/broadcasters/juce_AsyncUpdater.h
@@ -48,14 +48,17 @@ public:
     //==============================================================================
     /** Causes the callback to be triggered at a later time.
 
-        This method returns immediately, having made sure that a callback
-        to the handleAsyncUpdate() method will occur as soon as possible.
+        This method returns immediately, after which a callback to the
+        handleAsyncUpdate() method will be made by the message thread as
+        soon as possible.
 
-        If an update callback is already pending but hasn't happened yet, calls
-        to this method will be ignored.
+        If an update callback is already pending but hasn't happened yet, calling
+        this method will have no effect.
 
-        It's thread-safe to call this method from any number of threads without
-        needing to worry about locking.
+        It's thread-safe to call this method from any thread, BUT beware of calling
+        it from a real-time (e.g. audio) thread, because it involves posting a message
+        to the system queue, which means it may block (and in general will do on
+        most OSes).
     */
     void triggerAsyncUpdate();