diff --git a/mu4e/mu4e-headers.el b/mu4e/mu4e-headers.el
index adc7ff89..4bd2b6bd 100644
--- a/mu4e/mu4e-headers.el
+++ b/mu4e/mu4e-headers.el
@@ -986,8 +986,10 @@ header."
   "Move to the next header for which FUNC returns non-`nil',
 starting from the current position. FUNC takes one argument, the
 msg s-expression for the corresponding header. If BACKWARD is
-non-`nil', search backwards."
-  (let ((pos) (search-func (if backward 'search-backward 'search-forward)))
+non-`nil', search backwards. Returns the new position, or `nil' if
+nothing was found."
+  (let ((pos)
+	 (search-func (if backward 'search-backward 'search-forward)))
     (save-excursion
       (while (and (null pos)
 	       (funcall search-func mu4e~headers-docid-pre nil t))
diff --git a/mu4e/mu4e.texi b/mu4e/mu4e.texi
index ffacbe3b..d8c23a49 100644
--- a/mu4e/mu4e.texi
+++ b/mu4e/mu4e.texi
@@ -2380,11 +2380,13 @@ action}
 @end itemize
 
 @noindent
-You can also write your own functions without using the above. If you want to
-do so, key useful functions are @code{mu4e-message-at-point} (see below),
-@code{mu4e-headers-for-each} (to iterate over all headers, see its docstring)
-and @code{mu4e-view-for-each-part} (to iterate over all parts/attachments, see
-its docstring).
+You can also write your own functions without using the above. If you
+want to do so, key useful functions are @code{mu4e-message-at-point}
+(see below), @code{mu4e-headers-for-each} (to iterate over all headers,
+see its docstring) and @code{mu4e-view-for-each-part} (to iterate over
+all parts/attachments, see its docstring). Another useful function is
+@code{mu4e-headers-find-if}, which searches for a message matching a
+certain pattern; again, see its docstring.
 
 @node Available functions
 @section Available functions