diff --git a/src/pyj/read_book/read_aloud.pyj b/src/pyj/read_book/read_aloud.pyj
index 88c557e7b0..82b64d3269 100644
--- a/src/pyj/read_book/read_aloud.pyj
+++ b/src/pyj/read_book/read_aloud.pyj
@@ -188,6 +188,8 @@ class ReadAloud:
         if ev.key is 'Escape':
             self.hide()
             return
+        # Note that in the standalone viewer MediaPlayPause is currently broken
+        # in Qt: https://bugreports.qt.io/browse/QTBUG-89915
         if ev.key is ' ' or ev.key is 'MediaPlayPause' or ev.key is 'PlayPause':
             self.toggle()
             return