diff --git a/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml b/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
index 58903f8027d2..1002e2e581fa 100644
--- a/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
+++ b/pkgs/development/haskell-modules/configuration-hackage2nix/main.yaml
@@ -90,7 +90,6 @@ extra-packages:
   - haddock-api == 2.23.*               # required on GHC < 8.10.x
   - haddock-library ==1.7.*             # required by stylish-cabal-0.5.0.0
   - happy == 1.19.12                    # for ghcjs
-  - hermes-json == 0.2.*                # 2023-03-22: for nix-output-monitor-2.0.0.5
   - hinotify == 0.3.9                   # for xmonad-0.26: https://github.com/kolmodin/hinotify/issues/29
   - hlint == 3.2.8                      # 2022-09-21: needed for hls on ghc 8.8
   - hlint == 3.4.1                      # 2022-09-21: needed for hls with ghc-lib-parser 9.2
diff --git a/pkgs/development/haskell-modules/hackage-packages.nix b/pkgs/development/haskell-modules/hackage-packages.nix
index 9dce07275c67..d8a86f3a9778 100644
--- a/pkgs/development/haskell-modules/hackage-packages.nix
+++ b/pkgs/development/haskell-modules/hackage-packages.nix
@@ -138755,30 +138755,6 @@ self: {
        license = lib.licenses.bsd3;
      }) {};
 
-  "hermes-json_0_2_0_1" = callPackage
-    ({ mkDerivation, aeson, attoparsec, attoparsec-iso8601, base
-     , bytestring, containers, deepseq, dlist, hedgehog, mtl, scientific
-     , tasty, tasty-hedgehog, text, time, time-compat, transformers
-     , unliftio, unliftio-core
-     }:
-     mkDerivation {
-       pname = "hermes-json";
-       version = "0.2.0.1";
-       sha256 = "1i10nmblh6zxbqpqk5z5r97334j6x37kgw459i4icm6c4hi55k4l";
-       libraryHaskellDepends = [
-         attoparsec attoparsec-iso8601 base bytestring deepseq dlist mtl
-         scientific text time time-compat transformers unliftio
-         unliftio-core
-       ];
-       testHaskellDepends = [
-         aeson base bytestring containers hedgehog scientific tasty
-         tasty-hedgehog text time
-       ];
-       description = "Fast JSON decoding via simdjson C++ bindings";
-       license = lib.licenses.mit;
-       hydraPlatforms = lib.platforms.none;
-     }) {};
-
   "hermes-json" = callPackage
     ({ mkDerivation, aeson, attoparsec, attoparsec-iso8601, base
      , bytestring, containers, deepseq, dlist, hedgehog, primitive