diff --git a/gap-congruence.spec b/gap-congruence.spec
index 44600bf..55121c7 100644
--- a/gap-congruence.spec
+++ b/gap-congruence.spec
@@ -24,7 +24,7 @@ License:        GPL-2.0+
 Group:          Productivity/Scientific/Math
 Url:            http://www.cs.st-andrews.ac.uk/~alexk/congruence/
 
-Source:         ftp://ftp.gap-system.org/pub/gap/gap4/tar.bz2/packages/congruence-%version.tar.bz2
+Source:         https://www.gap-system.org/pub/gap/gap4/tar.bz2/packages/congruence-%version.tar.bz2
 BuildRequires:  gap-rpm-devel
 BuildRequires:  xz
 BuildArch:      noarch