diff --git a/pkgs/development/tools/parsing/bison/3.x.nix b/pkgs/development/tools/parsing/bison/3.x.nix
index 9c75e93bb1c..921f5d2d948 100644
--- a/pkgs/development/tools/parsing/bison/3.x.nix
+++ b/pkgs/development/tools/parsing/bison/3.x.nix
@@ -1,11 +1,11 @@
 { stdenv, hostPlatform, fetchurl, m4, perl, help2man }:
 
 stdenv.mkDerivation rec {
-  name = "bison-3.0.4";
+  name = "bison-3.0.5";
 
   src = fetchurl {
     url = "mirror://gnu/bison/${name}.tar.gz";
-    sha256 = "b67fd2daae7a64b5ba862c66c07c1addb9e6b1b05c5f2049392cfd8a2172952e";
+    sha256 = "0rnml9spd6p0i5qy9g4r82drwdr09r1z9cf4p89agbrkxqmrsffd";
   };
 
   patches = stdenv.lib.optional hostPlatform.isDarwin stdenv.secure-format-patch;