diff --git a/gnu/packages/games.scm b/gnu/packages/games.scm
index 9329e34c32..82a9660b2a 100644
--- a/gnu/packages/games.scm
+++ b/gnu/packages/games.scm
@@ -4196,7 +4196,7 @@ (define-public pioneers
     (version "15.6")
     (source (origin
               (method url-fetch)
-              (uri (string-append "http://downloads.sourceforge.net/pio/"
+              (uri (string-append "https://downloads.sourceforge.net/pio/"
                                   "pioneers-" version ".tar.gz"))
               (sha256
                (base32