diff --git a/lisp/calendar/calendar.el b/lisp/calendar/calendar.el
index acacaf345dc..75a942c6030 100644
--- a/lisp/calendar/calendar.el
+++ b/lisp/calendar/calendar.el
@@ -2354,7 +2354,8 @@ returned is (month year)."
                        (completion-table-with-metadata
                         (completion-table-case-fold
                          (append month-array nil))
-                        `((category . calendar-month)))
+                        `((category . calendar-month)
+                          (display-sort-function . identity)))
                        nil t nil nil defmon)
                       (calendar-make-alist month-array 1) t)))
          (defday (calendar-extract-day default-date))
diff --git a/lisp/minibuffer.el b/lisp/minibuffer.el
index abf55164995..1f33bda5f65 100644
--- a/lisp/minibuffer.el
+++ b/lisp/minibuffer.el
@@ -1197,8 +1197,7 @@ styles for specific categories, such as files, buffers, etc."
     (project-file (styles . (substring)))
     (xref-location (styles . (substring)))
     (info-menu (styles . (basic substring)))
-    (symbol-help (styles . (basic shorthand substring)))
-    (calendar-month (display-sort-function . identity)))
+    (symbol-help (styles . (basic shorthand substring))))
   "Default settings for specific completion categories.
 
 Each entry has the shape (CATEGORY . ALIST) where ALIST is