diff --git a/pkgs/by-name/gi/gildas/package.nix b/pkgs/by-name/gi/gildas/package.nix
index f8cb4faa3b7b..fed1a59a41f1 100644
--- a/pkgs/by-name/gi/gildas/package.nix
+++ b/pkgs/by-name/gi/gildas/package.nix
@@ -2,7 +2,8 @@
   lib,
   stdenv,
   fetchurl,
-  gtk2-x11,
+  gtk3,
+  gtk3-x11,
   pkg-config,
   python3,
   gfortran,
@@ -21,6 +22,7 @@ let
       setuptools
     ]
   );
+  gtk3' = if stdenv.hostPlatform.isDarwin then gtk3-x11 else gtk3;
 in
 
 stdenv.mkDerivation rec {
@@ -48,7 +50,7 @@ stdenv.mkDerivation rec {
   ];
 
   buildInputs = [
-    gtk2-x11
+    gtk3'
     cfitsio
     python3Env
     ncurses
@@ -105,7 +107,7 @@ stdenv.mkDerivation rec {
       extensible. GILDAS is written in Fortran-90, with a
       few parts in C/C++ (mainly keyboard interaction,
       plotting, widgets).'';
-    homepage = "http://www.iram.fr/IRAMFR/GILDAS/gildas.html";
+    homepage = "https://www.iram.fr/IRAMFR/GILDAS/";
     license = lib.licenses.free;
     maintainers = [
       lib.maintainers.bzizou