diff --git a/pkgs/development/tools/parsing/byacc/default.nix b/pkgs/development/tools/parsing/byacc/default.nix
index 8542d415196..79e171d5fd7 100644
--- a/pkgs/development/tools/parsing/byacc/default.nix
+++ b/pkgs/development/tools/parsing/byacc/default.nix
@@ -2,14 +2,14 @@
 
 stdenv.mkDerivation rec {
   pname = "byacc";
-  version = "20191119";
+  version = "20191125";
 
   src = fetchurl {
     urls = [
       "ftp://ftp.invisible-island.net/byacc/${pname}-${version}.tgz"
       "https://invisible-mirror.net/archives/byacc/${pname}-${version}.tgz"
     ];
-    sha256 = "0ch8y9g7b3lnw1r76p65gvdnbpwd60d4pghgadid122fcq7566p2";
+    sha256 = "1phw8410ly3msv03dmjfi8xkmrl1lrrk928fp1489amg6sz2w707";
   };
 
   configureFlags = [