diff --git a/pkgs/development/libraries/physics/hepmc3/default.nix b/pkgs/development/libraries/physics/hepmc3/default.nix
index 2e9a6261560e..ddced644e357 100644
--- a/pkgs/development/libraries/physics/hepmc3/default.nix
+++ b/pkgs/development/libraries/physics/hepmc3/default.nix
@@ -20,7 +20,7 @@ stdenv.mkDerivation rec {
   version = "3.3.1";
 
   src = fetchurl {
-    url = "http://hepmc.web.cern.ch/hepmc/releases/HepMC3-${version}.tar.gz";
+    url = "https://hepmc.web.cern.ch/hepmc/releases/HepMC3-${version}.tar.gz";
     sha256 = "sha256-CCQBYLDyjcMpOqTWHOZeLWfNWXrPb6ykOfLkZiX355M=";
   };