diff --git a/pkgs/os-specific/linux/nixos-rebuild/nixos-rebuild.sh b/pkgs/os-specific/linux/nixos-rebuild/nixos-rebuild.sh
index 47179afe515f..5874f334fedb 100644
--- a/pkgs/os-specific/linux/nixos-rebuild/nixos-rebuild.sh
+++ b/pkgs/os-specific/linux/nixos-rebuild/nixos-rebuild.sh
@@ -295,7 +295,7 @@ fi
 
 # Resolve the flake.
 if [[ -n $flake ]]; then
-    flake=$(nix "${flakeFlags[@]}" flake info --json "${extraBuildFlags[@]}" "${lockFlags[@]}" -- "$flake" | jq -r .url)
+    flake=$(nix "${flakeFlags[@]}" flake metadata --json "${extraBuildFlags[@]}" "${lockFlags[@]}" -- "$flake" | jq -r .url)
 fi
 
 # Find configuration.nix and open editor instead of building.
diff --git a/pkgs/tools/package-management/nix/default.nix b/pkgs/tools/package-management/nix/default.nix
index d39af405da53..352a6a546656 100644
--- a/pkgs/tools/package-management/nix/default.nix
+++ b/pkgs/tools/package-management/nix/default.nix
@@ -213,13 +213,13 @@ in rec {
 
   nixUnstable = lib.lowPrio (callPackage common rec {
     name = "nix-2.4${suffix}";
-    suffix = "pre20210308_1c0e3e4";
+    suffix = "pre20210317_8a5203d";
 
     src = fetchFromGitHub {
       owner = "NixOS";
       repo = "nix";
-      rev = "1c0e3e453d41b869e4ac7e25dc1c00c349a7c411";
-      sha256 = "17killwp42d25f17yq2jida64j7d0ipz6zish78iqi450yrd9wrd";
+      rev = "8a5203d3b836497c2c5f157f85008aa8bcb6a1d2";
+      sha256 = "IMzdmoWAX6Lerhslsf7h2814xjJolPnl2bICDixRgdk=";
     };
 
     inherit storeDir stateDir confDir boehmgc;