diff --git a/pkgs/by-name/sg/sgt-puzzles/package.nix b/pkgs/by-name/sg/sgt-puzzles/package.nix
index 0ddd97133e13..2e0b2b9768c2 100644
--- a/pkgs/by-name/sg/sgt-puzzles/package.nix
+++ b/pkgs/by-name/sg/sgt-puzzles/package.nix
@@ -21,7 +21,7 @@ stdenv.mkDerivation (finalAttrs: {
   version = "20260309.06e37f1";
 
   src = fetchurl {
-    url = "http://www.chiark.greenend.org.uk/~sgtatham/puzzles/puzzles-${finalAttrs.version}.tar.gz";
+    url = "https://www.chiark.greenend.org.uk/~sgtatham/puzzles/puzzles-${finalAttrs.version}.tar.gz";
     hash = "sha256-3Z/Qp8D/0DeJL9oZlKL6vx9BXvMVFa6MMnkStds/VHI=";
   };