diff --git a/pkgs/development/compilers/gcc/6/default.nix b/pkgs/development/compilers/gcc/6/default.nix
index acddc9081be..3edfb177b11 100644
--- a/pkgs/development/compilers/gcc/6/default.nix
+++ b/pkgs/development/compilers/gcc/6/default.nix
@@ -59,7 +59,7 @@ assert langGo -> langCC;
 with stdenv.lib;
 with builtins;
 
-let version = "6.2.0";
+let version = "6.3.0";
 
     # Whether building a cross-compiler for GNU/Hurd.
     crossGNU = cross != null && cross.config == "i586-pc-gnu";
@@ -216,7 +216,7 @@ stdenv.mkDerivation ({
 
   src = fetchurl {
     url = "mirror://gnu/gcc/gcc-${version}/gcc-${version}.tar.bz2";
-    sha256 = "1idpf43988v1a6i8lw9ak1r7igcfg1bm5kn011iydlr2qygmhi4r";
+    sha256 = "17xjz30jb65hcf714vn9gcxvrrji8j20xm7n33qg1ywhyzryfsph";
   };
 
   inherit patches;