diff --git a/gap-normalizinterface.spec b/gap-normalizinterface.spec
index 69dce4f..571f631 100644
--- a/gap-normalizinterface.spec
+++ b/gap-normalizinterface.spec
@@ -24,7 +24,7 @@ License:        GPL-2.0+
 Group:          Productivity/Scientific/Math
 Url:            https://www.normaliz.uni-osnabrueck.de
 
-Source:         ftp://ftp.gap-system.org/pub/gap/gap4/tar.bz2/packages/NormalizInterface-%version.tar.bz2
+Source:         https://www.gap-system.org/pub/gap/gap4/tar.bz2/packages/NormalizInterface-%version.tar.bz2
 BuildRequires:  fdupes
 BuildRequires:  libtool
 BuildRequires:  gcc-c++