diff --git a/changelog.d/5-internal/unclutter-ormolu-script b/changelog.d/5-internal/unclutter-ormolu-script
new file mode 100644
index 0000000000..ffb56f1bde
--- /dev/null
+++ b/changelog.d/5-internal/unclutter-ormolu-script
@@ -0,0 +1 @@
+ormolu: don't redundantly add language extensions from dead package-defaults.yaml
diff --git a/docs/src/developer/developer/editor-setup.md b/docs/src/developer/developer/editor-setup.md
index 7b39f8a463..45504975da 100644
--- a/docs/src/developer/developer/editor-setup.md
+++ b/docs/src/developer/developer/editor-setup.md
@@ -92,19 +92,18 @@ or check the entire repository.  This takes about 10 seconds.
 Vim integration is [linked
 here](https://github.com/tweag/ormolu#editor-integration).
 
-If you use sdiehl's module, you you need to collect the language extensions from `package-defaults.yaml`:
+If you use sdiehl's module, you may need to collect the language extensions from a cabal file:
 
 ```
     let g:ormolu_options = ["--ghc-opt -XAllowAmbiguousTypes --ghc-opt -XBangPatterns --ghc-opt -XConstraintKinds --ghc-opt -XDataKinds --ghc-opt -XDefaultSignatures --ghc-opt -XDerivingStrategies --ghc-opt -XDeriveFunctor --ghc-opt -XDeriveGeneric --ghc-opt -XDeriveLift --ghc-opt -XDeriveTraversable --ghc-opt -XEmptyCase --ghc-opt -XFlexibleContexts --ghc-opt -XFlexibleInstances --ghc-opt -XFunctionalDependencies --ghc-opt -XGADTs --ghc-opt -XInstanceSigs --ghc-opt -XKindSignatures --ghc-opt -XLambdaCase --ghc-opt -XMultiParamTypeClasses --ghc-opt -XMultiWayIf --ghc-opt -XNamedFieldPuns --ghc-opt -XNoImplicitPrelude --ghc-opt -XOverloadedStrings --ghc-opt -XPackageImports --ghc-opt -XPatternSynonyms --ghc-opt -XPolyKinds --ghc-opt -XQuasiQuotes --ghc-opt -XRankNTypes --ghc-opt -XScopedTypeVariables --ghc-opt -XStandaloneDeriving --ghc-opt -XTemplateHaskell --ghc-opt -XTupleSections --ghc-opt -XTypeApplications --ghc-opt -XTypeFamilies --ghc-opt -XTypeFamilyDependencies --ghc-opt -XTypeOperators --ghc-opt -XUndecidableInstances --ghc-opt -XViewPatterns"]
 ```
 
-If you want to be playful, you can look at how `tools/ormolu.sh`
-collects the language extensions automatically and see if you can get
-it to work here.
+**EDIT:** this may no longer be necessary, as the ormolu version we
+  use consults the cabal files for enabled language extensions.
 
 ## VSCode
 
-The project can be loaded into the [Haskell Language Server](https://github.com/haskell/haskell-language-server). 
+The project can be loaded into the [Haskell Language Server](https://github.com/haskell/haskell-language-server).
 This gives type checking, code completion, HLint hints, formatting with Ormolu, lookup of definitions and references, etc..
 All needed dependencies (like the `haskell-language-server` and `stack` binaries) are provided by `shell.nix`.
 
@@ -115,5 +114,5 @@ Setup steps:
 - Reload the window as proposed by the `Nix Environment Selector` plugin
 
 An alternative way to make these dependencies accessible to VSCode is to start it in the `direnv` environment.
-I.e. from a shell that's current working directory is in the project. The drawbacks of this approach are 
+I.e. from a shell that's current working directory is in the project. The drawbacks of this approach are
 that it only works locally (not on a remote connection) and one VSCode process needs to be started per project.
diff --git a/package-defaults.yaml b/package-defaults.yaml
deleted file mode 100644
index eec3552b4a..0000000000
--- a/package-defaults.yaml
+++ /dev/null
@@ -1,49 +0,0 @@
-ghc-options:
-- -O2
-- -Wall
-- -Wincomplete-uni-patterns
-- -Wincomplete-record-updates
-- -Wpartial-fields
-- -fwarn-tabs
-# These errors pop up from time to time but haven't caused any serious trouble yet
-- -optP-Wno-nonportable-include-path
-
-default-extensions:
-- AllowAmbiguousTypes
-- BangPatterns
-- ConstraintKinds
-- DataKinds
-- DefaultSignatures
-- DerivingStrategies
-- DerivingVia
-- DeriveFunctor
-- DeriveGeneric
-- DeriveLift
-- DeriveTraversable
-- EmptyCase
-- FlexibleContexts
-- FlexibleInstances
-- FunctionalDependencies
-- GADTs
-- InstanceSigs
-- KindSignatures
-- LambdaCase
-- MultiParamTypeClasses
-- MultiWayIf
-- NamedFieldPuns
-- NoImplicitPrelude
-- OverloadedStrings
-- PackageImports
-- PatternSynonyms
-- PolyKinds
-- QuasiQuotes
-- RankNTypes
-- ScopedTypeVariables
-- StandaloneDeriving
-- TupleSections
-- TypeApplications
-- TypeFamilies
-- TypeFamilyDependencies
-- TypeOperators
-- UndecidableInstances
-- ViewPatterns
diff --git a/tools/ormolu.sh b/tools/ormolu.sh
index 44a9452e70..901baa11e0 100755
--- a/tools/ormolu.sh
+++ b/tools/ormolu.sh
@@ -61,9 +61,8 @@ if [ "$(git status -s | grep -v \?\?)" != "" ]; then
     fi
 fi
 
-readarray -t EXTS < <(sed -n '/^default-extensions:/,$ { s/^- //p }' < package-defaults.yaml)
 echo "ormolu mode: $ARG_ORMOLU_MODE"
-echo "language extensions: ${EXTS[@]}"
+echo "language extensions are taken from the resp. cabal files"
 
 FAILURES=0
 
@@ -84,7 +83,7 @@ for hsfile in $files; do
     FAILED=0
 
     # run in background so that we can detect Ctrl-C properly
-    ormolu --mode $ARG_ORMOLU_MODE --check-idempotence ${EXTS[@]/#/'-o -X'} "$hsfile" &
+    ormolu --mode $ARG_ORMOLU_MODE --check-idempotence "$hsfile" &
     wait $! && err=0 || err=$?
 
     if [ "$err" == "100" ]; then