diff --git a/guix/build/download.scm b/guix/build/download.scm
index 41583e8143..951ca3a57a 100644
--- a/guix/build/download.scm
+++ b/guix/build/download.scm
@@ -744,6 +744,7 @@ (define (fetch uri file)
                                          (progress-reporter/file
                                           (uri-abbreviation uri) size)))
               (newline)))
+          (close-port port)
           file)))
       ((ftp)
        (false-if-exception* (ftp-fetch uri file