diff --git a/pkgs/development/libraries/udunits/default.nix b/pkgs/development/libraries/udunits/default.nix
index 8fa974a95e2..b8ffc16f905 100644
--- a/pkgs/development/libraries/udunits/default.nix
+++ b/pkgs/development/libraries/udunits/default.nix
@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
     buildInputs = [ expat ];
 
     meta = with stdenv.lib; {
-      homepage = http://www.unidata.ucar.edu/software/udunits/;
+      homepage = https://www.unidata.ucar.edu/software/udunits/;
       description = "A C-based package for the programatic handling of units of physical quantities";
       license = licenses.bsdOriginal;
       platforms = platforms.linux;