diff --git a/README.org b/README.org
index c247123..d6cc25f 100644
--- a/README.org
+++ b/README.org
@@ -88,7 +88,7 @@ Arguments are listed next to predicate names, where applicable.
 Note that, for convenience, standard numeric comparator function symbols (~<~, ~=~, etc.) do not need to be quoted when passed as an argument to these predicates.  The resemblance to infix notation is coincidental.  See examples in documentation.
 
 +  ~category (&optional categories)~ :: Return non-nil if current heading is in one or more of ~CATEGORIES~ (a list of strings).
-+  ~clocked (&key from to on)~ :: Return non-nil if current entry was clocked in given period.  If no arguments are specified, return non-nil if entry was clocked at any time.  If ~FROM~, return non-nil if entry was clocked on or after ~FROM~.  If ~TO~, return non-nil if entry was clocked on or before ~TO~.  If ~ON~, return non-nil if entry was clocked on date ~ON~.  ~FROM~, ~TO~, and ~ON~ should be strings parseable by ~parse-time-string~ but may omit the time value.  Note: See macrolet in ~org-ql-query~ which pre-processes arguments to this function, parsing timestamp strings into Unix timestamps and accepting `:on' keyword.
++  ~clocked (&key from to on)~ :: Return non-nil if current entry was clocked in given period.  If no arguments are specified, return non-nil if entry was clocked at any time.  If ~FROM~, return non-nil if entry was clocked on or after ~FROM~.  If ~TO~, return non-nil if entry was clocked on or before ~TO~.  If ~ON~, return non-nil if entry was clocked on date ~ON~.  ~FROM~, ~TO~, and ~ON~ should be strings parseable by ~parse-time-string~ but may omit the time value.  Note: Clock entries are expected to be clocked out.  Currently clocked entries (i.e. with unclosed timestamp ranges) are ignored.
 +  ~closed (&optional comparator target-date)~ :: Return non-nil if entry's closed date compares with ~TARGET-DATE~ using ~COMPARATOR~.  ~TARGET-DATE~ should be a string parseable by ~date-to-day~.  ~COMPARATOR~ should be a function (like ~<=~).
 +  ~date (&optional comparator target-date type)~ :: Return non-nil if Org entry at point has date of ~TYPE~ that compares with ~TARGET-DATE~ using ~COMPARATOR~.  Checks all Org-formatted timestamp strings in entry.  ~TYPE~ may be ~active~, ~inactive~, or ~all~, to control whether active, inactive, or all timestamps are checked.  Ranges of each type are also checked.  ~TARGET-DATE~ should be a string parseable by ~date-to-day~.  ~COMPARATOR~ should be a function (like ~<=~).
 +  ~deadline (&optional comparator target-date)~ :: Return non-nil if entry's deadline compares with ~TARGET-DATE~ using ~COMPARATOR~.  ~TARGET-DATE~ should be a string parseable by ~date-to-day~.  ~COMPARATOR~ should be a function (like ~<=~).
diff --git a/org-ql.el b/org-ql.el
index 4c28941..538d130 100644
--- a/org-ql.el
+++ b/org-ql.el
@@ -310,9 +310,9 @@ If ON, return non-nil if entry was clocked on date ON.
 FROM, TO, and ON should be strings parseable by
 `parse-time-string' but may omit the time value.
 
-Note: See macrolet in `org-ql-query' which pre-processes
-arguments to this function, parsing timestamp strings into Unix
-timestamps and accepting `:on' keyword."
+Note: Clock entries are expected to be clocked out.  Currently
+clocked entries (i.e. with unclosed timestamp ranges) are
+ignored."
   ;; NOTE: FROM and TO are actually expected to be Unix timestamps.  The docstring is written
   ;; for end users, for which the arguments are pre-processed by `org-ql-query'.
   ;; FIXME: This assumes every "clocked" entry is a range.  Unclosed clock entries are not handled.