1 files changed, 3 insertions, 0 deletions

diff --git a/src/keymap.c b/src/keymap.c
index 4583d3121df..74a1cc15024 100644
--- a/src/keymap.c
+++ b/src/keymap.c
@@ -3851,6 +3851,9 @@ keymaps have no binding for the current key sequence but
 `read-key-sequence' replaces the matching suffix with its binding, and
 continues with the new sequence.
 
+If the binding is a function, it is called with one argument (the prompt)
+and its return value (a key sequence) is used.
+
 The events that come from bindings in `function-key-map' are not
 themselves looked up in `function-key-map'.