diff --git a/kgraphviewer.spec b/kgraphviewer.spec
index 86e8148..afbed24 100644
--- a/kgraphviewer.spec
+++ b/kgraphviewer.spec
@@ -24,7 +24,7 @@ Summary:        Graphviz dot graph file viewer
 License:        GPL-2.0-only
 Group:          Development/Tools/Other
 URL:            https://www.kde.org/applications/graphics/kgraphviewer/
-Source:         http://download.kde.org/stable/%{name}/%{version}/src/%{name}-%{version}.tar.xz
+Source:         https://download.kde.org/stable/%{name}/%{version}/src/%{name}-%{version}.tar.xz
 BuildRequires:  boost-devel
 BuildRequires:  graphviz-devel
 BuildRequires:  kcoreaddons-devel