diff --git a/pkgs/development/compilers/rustc/head.nix b/pkgs/development/compilers/rustc/head.nix
index 4899e51e2ef4..5aad9bfa5fff 100644
--- a/pkgs/development/compilers/rustc/head.nix
+++ b/pkgs/development/compilers/rustc/head.nix
@@ -16,6 +16,10 @@ assert !stdenv.isFreeBSD;
   expected. Once the language is stable (1.0) , we might want to
   switch it to use nix's packaged rust compiler.
 
+
+NOTE : some derivation depend on rust. When updating this, please make
+sure those derivations still compile. (racer, for example).
+
 */
 
 let shortVersion = "0.13-dev";
diff --git a/pkgs/development/tools/rust/racer/default.nix b/pkgs/development/tools/rust/racer/default.nix
index b6b0f6f63537..c82413376bd6 100644
--- a/pkgs/development/tools/rust/racer/default.nix
+++ b/pkgs/development/tools/rust/racer/default.nix
@@ -9,8 +9,8 @@ stdenv.mkDerivation rec {
   name = "racer-git-2014-12-04";
   src = fetchgit {
     url = https://github.com/phildawes/racer;
-    rev = "cc633ad2477cb064ba6e4d23b58c124c8521410c";
-    sha256 = "1nqlgdqnqhzbnbxvhs60gk5hjzrxfq8blyh1riiknxdlq5kqaky7";
+    rev = "bf73c05ac719cd3b0f8d8f9e0ecb066ede6aa9d9";
+    sha256 = "1159fsfca2kqvlajp8sawrskip7hc0rppk8vhwxa2vw8zznp56w0";
   };
 
   buildInputs = [ rust makeWrapper ];