diff --git a/maintainers/scripts/haskell/hydra-report.hs b/maintainers/scripts/haskell/hydra-report.hs
index 360b9f2058d..6f154d90f06 100755
--- a/maintainers/scripts/haskell/hydra-report.hs
+++ b/maintainers/scripts/haskell/hydra-report.hs
@@ -1,6 +1,6 @@
 #! /usr/bin/env nix-shell
 #! nix-shell -p "haskellPackages.ghcWithPackages (p: [p.aeson p.req])"
-#! nix-shell -p hydra-unstable
+#! nix-shell -p hydra_unstable
 #! nix-shell -i runhaskell
 
 {-
diff --git a/nixos/modules/services/continuous-integration/hydra/default.nix b/nixos/modules/services/continuous-integration/hydra/default.nix
index 90adab7fbf2..9440382e66a 100644
--- a/nixos/modules/services/continuous-integration/hydra/default.nix
+++ b/nixos/modules/services/continuous-integration/hydra/default.nix
@@ -99,8 +99,8 @@ in
 
       package = mkOption {
         type = types.package;
-        default = pkgs.hydra-unstable;
-        defaultText = literalExpression "pkgs.hydra-unstable";
+        default = pkgs.hydra_unstable;
+        defaultText = literalExpression "pkgs.hydra_unstable";
         description = "The Hydra package.";
       };
 
diff --git a/nixos/tests/hydra/default.nix b/nixos/tests/hydra/default.nix
index 9fc787842d8..baf18afbc56 100644
--- a/nixos/tests/hydra/default.nix
+++ b/nixos/tests/hydra/default.nix
@@ -11,7 +11,7 @@ let
   inherit (import ./common.nix { inherit system; }) baseConfig;
 
   hydraPkgs = {
-    inherit (pkgs) hydra-unstable;
+    inherit (pkgs) hydra_unstable;
   };
 
   makeHydraTest = with pkgs.lib; name: package: makeTest {
diff --git a/pkgs/development/tools/misc/hydra/unstable.nix b/pkgs/development/tools/misc/hydra/unstable.nix
index 7d3521702a7..e375a26b737 100644
--- a/pkgs/development/tools/misc/hydra/unstable.nix
+++ b/pkgs/development/tools/misc/hydra/unstable.nix
@@ -173,7 +173,7 @@ in stdenv.mkDerivation rec {
 
   passthru = {
     inherit perlDeps;
-    tests.basic = nixosTests.hydra.hydra-unstable;
+    tests.basic = nixosTests.hydra.hydra_unstable;
   };
 
   meta = with lib; {
diff --git a/pkgs/top-level/aliases.nix b/pkgs/top-level/aliases.nix
index 31e4fa42250..c59baccc502 100644
--- a/pkgs/top-level/aliases.nix
+++ b/pkgs/top-level/aliases.nix
@@ -549,7 +549,8 @@ mapAliases ({
   holochain-go = throw "holochain-go was abandoned by upstream"; # Added 2022-01-01
   htmlTidy = throw "'htmlTidy' has been renamed to/replaced by 'html-tidy'"; # Converted to throw 2022-02-22
   ht-rust = xh; # Added 2021-02-13
-  hydra-flakes = throw "hydra-flakes: Flakes support has been merged into Hydra's master. Please use `hydra-unstable` now"; # Added 2020-04-06
+  hydra-flakes = throw "hydra-flakes: Flakes support has been merged into Hydra's master. Please use `hydra_unstable` now"; # Added 2020-04-06
+  hydra-unstable = hydra_unstable; # added 2022-05-10
 
   ### I ###
 
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index e98ae93e1fc..8e5503a43bb 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -17830,7 +17830,7 @@ with pkgs;
 
   hwloc = callPackage ../development/libraries/hwloc {};
 
-  hydra-unstable = callPackage ../development/tools/misc/hydra/unstable.nix { nix = nixVersions.nix_2_6; };
+  hydra_unstable = callPackage ../development/tools/misc/hydra/unstable.nix { nix = nixVersions.nix_2_6; };
 
   hydra-cli = callPackage ../development/tools/misc/hydra-cli { };
 
diff --git a/pkgs/top-level/release-haskell.nix b/pkgs/top-level/release-haskell.nix
index a1e72c90bea..21c54975a28 100644
--- a/pkgs/top-level/release-haskell.nix
+++ b/pkgs/top-level/release-haskell.nix
@@ -4,7 +4,7 @@
   https://hydra.nixos.org/jobset/nixpkgs/haskell-updates.
 
   To debug this expression you can use `hydra-eval-jobs` from
-  `pkgs.hydra-unstable` which prints the jobset description
+  `pkgs.hydra_unstable` which prints the jobset description
   to `stdout`:
 
   $ hydra-eval-jobs -I . pkgs/top-level/release-haskell.nix