diff --git a/README.org b/README.org
index bb6c589..afd06f3 100644
--- a/README.org
+++ b/README.org
@@ -557,6 +557,7 @@ Simple links may also be written manually in either sexp or non-sexp form, like:
 
 *Fixes*
 + Predicate ~property~ when called with argument form ~(property "PROPERTY-NAME" :inherit t)~.  ([[https://github.com/alphapapa/org-ql/issues/460][#460]].  Thanks to [[https://github.com/Stewmath][Stewmath]] for reporting.)
++ Predicate ~level~'s preamble optimizer allows expressions in place of the numeric argument (see [[https://github.com/alphapapa/org-ql/issues/460][#460]].  Thanks to [[https://github.com/Stewmath][Stewmath]] for reporting.)
 + Reading of view settings from Org links in upcoming Emacs version.  ([[https://github.com/alphapapa/org-ql/issues/461][#461]].  Thanks to [[https://github.com/snogge][Ola Nilsson]] for help debugging, and for maintaining [[https://github.com/jorgenschaefer/emacs-buttercup][Buttercup]].)
 
 ** 0.8.8
diff --git a/org-ql.el b/org-ql.el
index 9ff8d71..40266e3 100644
--- a/org-ql.el
+++ b/org-ql.el
@@ -1534,7 +1534,8 @@ COMPARATOR may be `<', `<=', `>', or `>='."
                ;; is "h:" while the user is typing.
                (list :regexp (rx bol (1+ "*") " ")
                      :case-fold t))
-              (`(,predicate-names ,comparator-or-num ,num)
+              ((and `(,predicate-names ,comparator-or-num ,num)
+                    (guard (numberp num)))
                (let ((repeat (pcase comparator-or-num
                                ('< `(repeat 1 ,(1- num) "*"))
                                ('<= `(repeat 1 ,num "*"))
@@ -1543,7 +1544,8 @@ COMPARATOR may be `<', `<=', `>', or `>='."
                                ((pred integerp) `(repeat ,comparator-or-num ,num "*")))))
                  (list :regexp (rx-to-string `(seq bol ,repeat " ") t)
                        :case-fold t)))
-              (`(,predicate-names ,num)
+              ((and `(,predicate-names ,num)
+                    (guard (numberp num)))
                (list :regexp (rx-to-string `(seq bol (repeat ,num "*") " ") t)
                      :case-fold t)))
   ;; NOTE: It might be necessary to take into account `org-odd-levels'; see docstring for
diff --git a/org-ql.info b/org-ql.info
index c11c851..4222edd 100644
--- a/org-ql.info
+++ b/org-ql.info
@@ -1089,6 +1089,10 @@ File: README.info,  Node: 089-pre,  Next: 088,  Up: Changelog
      "PROPERTY-NAME" :inherit t)’.  (#460
      (https://github.com/alphapapa/org-ql/issues/460).  Thanks to
      Stewmath (https://github.com/Stewmath) for reporting.)
+   • Predicate ‘level’’s preamble optimizer allows expressions in place
+     of the numeric argument (see #460
+     (https://github.com/alphapapa/org-ql/issues/460).  Thanks to
+     Stewmath (https://github.com/Stewmath) for reporting.)
    • Reading of view settings from Org links in upcoming Emacs version.
      (#461 (https://github.com/alphapapa/org-ql/issues/461).  Thanks to
      Ola Nilsson (https://github.com/snogge) for help debugging, and for
@@ -2073,49 +2077,49 @@ Node: Links38939
 Node: Tips39626
 Node: Changelog39950
 Node: 089-pre40900
-Node: 08841554
-Node: 08742634
-Node: 08643862
-Node: 08544096
-Node: 08444752
-Node: 08345204
-Node: 08245545
-Node: 08145938
-Node: 0846359
-Node: 07449085
-Node: 07349310
-Node: 07250044
-Node: 07150965
-Node: 0751776
-Node: 06354642
-Node: 06255175
-Node: 06155482
-Node: 0656052
-Node: 05259108
-Node: 05159410
-Node: 0559835
-Node: 04961366
-Node: 04861648
-Node: 04761997
-Node: 04662406
-Node: 04562814
-Node: 04463175
-Node: 04363534
-Node: 04263737
-Node: 04163898
-Node: 0464145
-Node: 03268246
-Node: 03168649
-Node: 0368846
-Node: 02372146
-Node: 02272380
-Node: 02172660
-Node: 0272865
-Node: 0176943
-Node: Notes77044
-Node: Comparison with Org Agenda searches77206
-Node: org-sidebar78095
-Node: License78374
+Node: 08841799
+Node: 08742879
+Node: 08644107
+Node: 08544341
+Node: 08444997
+Node: 08345449
+Node: 08245790
+Node: 08146183
+Node: 0846604
+Node: 07449330
+Node: 07349555
+Node: 07250289
+Node: 07151210
+Node: 0752021
+Node: 06354887
+Node: 06255420
+Node: 06155727
+Node: 0656297
+Node: 05259353
+Node: 05159655
+Node: 0560080
+Node: 04961611
+Node: 04861893
+Node: 04762242
+Node: 04662651
+Node: 04563059
+Node: 04463420
+Node: 04363779
+Node: 04263982
+Node: 04164143
+Node: 0464390
+Node: 03268491
+Node: 03168894
+Node: 0369091
+Node: 02372391
+Node: 02272625
+Node: 02172905
+Node: 0273110
+Node: 0177188
+Node: Notes77289
+Node: Comparison with Org Agenda searches77451
+Node: org-sidebar78340
+Node: License78619
 
 End Tag Table