diff --git a/gap-4ti2interface.spec b/gap-4ti2interface.spec
index 5bc1c8e..7e6a294 100644
--- a/gap-4ti2interface.spec
+++ b/gap-4ti2interface.spec
@@ -24,7 +24,7 @@ License:        GPL-2.0
 Group:          Productivity/Scientific/Math
 URL:            http://homalg-project.github.io/homalg_project/4ti2Interface/
 
-Source:         http://www.gap-system.org/pub/gap/gap4/tar.bz2/packages/4ti2Interface-4ti2Interface-%version.tar.bz2
+Source:         https://www.gap-system.org/pub/gap/gap4/tar.bz2/packages/4ti2Interface-4ti2Interface-%version.tar.bz2
 BuildArch:      noarch
 BuildRoot:      %{_tmppath}/%{name}-%{version}-build
 BuildRequires:  gap-rpm-devel