diff --git a/pkgs/tools/text/uni2ascii/default.nix b/pkgs/tools/text/uni2ascii/default.nix
index d83e9393f941..fab6ac79de16 100644
--- a/pkgs/tools/text/uni2ascii/default.nix
+++ b/pkgs/tools/text/uni2ascii/default.nix
@@ -2,13 +2,20 @@
 
 stdenv.mkDerivation rec {
   pname = "uni2ascii";
-  version = "4.18";
+  version = "4.20";
 
   src = fetchurl {
     url = "https://billposer.org/Software/Downloads/uni2ascii-${version}.tar.gz";
-    sha256 = "03lklnzr6ngs4wqiqa7rifd246f441gfvardbsaa5l6fn9pbn94y";
+    hash = "sha256-7tjYOpwdLb0NfKTFJRmYg9cxfWiLQhtXjQmKJ7b/cFY=";
   };
 
+  patches = [
+    (fetchurl {
+      url = "https://github.com/Homebrew/formula-patches/raw/bb92449ad6b3878b4d6f472237152df28080df86/uni2ascii/uni2ascii-4.20.patch";
+      hash = "sha256-JQpSntoTbQ7fnmO5Km/pX071360/lOb9jYdxOK2oV/g=";
+    })
+  ];
+
   meta = {
     license = lib.licenses.gpl3;
     homepage = "http://billposer.org/Software/uni2ascii.html";