diff --git a/audio-manager.rkt b/audio-manager.rkt
index 0b7fba9..7956533 100644
--- a/audio-manager.rkt
+++ b/audio-manager.rkt
@@ -303,7 +303,7 @@
               (let ((dest-path (build-path opus-path path-part)))
                 (unless (directory-exists? (basedir dest-path))
                   (make-directory* (basedir dest-path)))
-		(rep-opus "Copying: ~a" path-part)
+		(rep-opus (format "Copying: ~a" path-part))
                 (copy-file path dest-path #:exists-ok? #t)
                 (set! copied-files (+ copied-files 1)))))
           )