diff --git a/lisp/progmodes/xref.el b/lisp/progmodes/xref.el
index 18fdd963fb..6a5361f852 100644
--- a/lisp/progmodes/xref.el
+++ b/lisp/progmodes/xref.el
@@ -1691,7 +1701,10 @@ xref--collect-matches-1
       (let* ((beg-column (- (match-beginning 0) line-beg))
              (end-column (- (match-end 0) line-beg))
              (loc (xref-make-file-location file line beg-column))
-             (summary (buffer-substring line-beg line-end)))
+             (summary (progn
+                        (unless syntax-needed
+                          (font-lock-ensure line-beg line-end))
+                        (buffer-substring line-beg line-end))))
         (add-face-text-property beg-column end-column 'xref-match
                                 t summary)
         (push (xref-make-match summary loc (- end-column beg-column))