diff --git a/pkgs/tools/package-management/nix/default.nix b/pkgs/tools/package-management/nix/default.nix
index 5c8341941ed6..2302476eb918 100644
--- a/pkgs/tools/package-management/nix/default.nix
+++ b/pkgs/tools/package-management/nix/default.nix
@@ -34,7 +34,7 @@ let
       ++ lib.optional withLibseccomp libseccomp
       ++ lib.optional ((stdenv.isLinux || stdenv.isDarwin) && is20)
           (aws-sdk-cpp.override {
-            apis = ["s3"];
+            apis = ["s3" "transfer"];
             customMemoryManagement = false;
           })
       ++ lib.optional fromGit boost;
@@ -144,12 +144,12 @@ in rec {
 
   nixUnstable = (lib.lowPrio (common rec {
     name = "nix-2.1${suffix}";
-    suffix = "pre6148_a4aac7f";
+    suffix = "pre6338_45bcf541";
     src = fetchFromGitHub {
       owner = "NixOS";
       repo = "nix";
-      rev = "a4aac7f88c59c97299027c9668461c637bbc6a72";
-      sha256 = "1250fg1rgzcd0qy960nhl2bw9hsc1a6pyz11rmxasr0h3j1a2z53";
+      rev = "45bcf5416a0ce53361fd37c6b27ba4ef6a34ce96";
+      sha256 = "0ps45n78wnczz99dd9fs54ydxwh2cjq73zbvmak0y49nhc3p0vvv";
     };
     fromGit = true;
   })) // { perl-bindings = perl-bindings {