diff --git a/pkgs/misc/drivers/epkowa/default.nix b/pkgs/misc/drivers/epkowa/default.nix
index 114568fdd52..26aa339f861 100644
--- a/pkgs/misc/drivers/epkowa/default.nix
+++ b/pkgs/misc/drivers/epkowa/default.nix
@@ -103,7 +103,7 @@ stdenv.mkDerivation rec {
 
   patches = [
     (fetchpatch {
-      url = "https://gitweb.gentoo.org/repo/gentoo.git/plain/media-gfx/iscan/files/iscan-2.28.1.3+libpng-1.5.patch";
+      url = "https://gitweb.gentoo.org/repo/gentoo.git/plain/media-gfx/iscan/files/iscan-2.28.1.3+libpng-1.5.patch?h=b6e4c805d53b49da79a0f64ef16bb82d6d800fcf";
       sha256 = "04y70qjd220dpyh771fiq50lha16pms98mfigwjczdfmx6kpj1jd";
     })
     ./firmware_location.patch