diff --git a/pkgs/by-name/cm/cmt/package.nix b/pkgs/by-name/cm/cmt/package.nix
index 8c4c005448c5..7efc670f70c8 100644
--- a/pkgs/by-name/cm/cmt/package.nix
+++ b/pkgs/by-name/cm/cmt/package.nix
@@ -10,7 +10,7 @@ stdenv.mkDerivation (finalAttrs: {
   version = "1.18";
 
   src = fetchurl {
-    url = "http://www.ladspa.org/download/cmt_${finalAttrs.version}.tgz";
+    url = "https://www.ladspa.org/download/cmt_${finalAttrs.version}.tgz";
     sha256 = "sha256-qC+GNt4fSto4ahmaAXqc13Wkm0nnFrEejdP3I8k99so=";
   };