diff --git a/guix/scripts/substitute-binary.scm b/guix/scripts/substitute-binary.scm
index 0fdec45..bfaebee 100755
--- a/guix/scripts/substitute-binary.scm
+++ b/guix/scripts/substitute-binary.scm
@@ -418,7 +418,10 @@ PORT.  REPORT-PROGRESS is a two-argument procedure such as that returned by
 
   ;; Since `http-fetch' in Guile 2.0.5 returns all the data once it's done,
   ;; don't pretend to report any progress in that case.
-  (if (version>? (version) "2.0.5")
+  (if (version>? (string-append (major-version) "."
+                                (minor-version) "."
+                                (micro-version))
+                 "2.0.5")
       (make-custom-binary-input-port "progress-port-proc"
                                      read! #f #f
                                      (cut close-port port))