diff --git a/pkgs/build-support/dart/fetch-dart-deps/setup-hook.sh b/pkgs/build-support/dart/fetch-dart-deps/setup-hook.sh
index 1a5f86e475c0..37ef74aa62dd 100644
--- a/pkgs/build-support/dart/fetch-dart-deps/setup-hook.sh
+++ b/pkgs/build-support/dart/fetch-dart-deps/setup-hook.sh
@@ -33,7 +33,7 @@ _setupPubCache() {
         cp -v "$deps/pubspec/pubspec.lock" .
         # Sometimes the pubspec.lock will get opened in write mode, even when offline.
         chmod u+w pubspec.lock
-    elif [ ! { diff -u pubspec.lock "$deps/pubspec/pubspec.lock" && diff -u pubspec.yaml "$deps/pubspec/pubspec.yaml" } ]; then
+    elif ! { diff -u pubspec.lock "$deps/pubspec/pubspec.lock" && diff -u pubspec.yaml "$deps/pubspec/pubspec.yaml"; }; then
         echo 1>&2 -e 'The pubspec.lock or pubspec.yaml of the project derivation differs from the one in the dependency derivation.' \
                    '\nYou most likely forgot to update the vendorHash while updating the sources.'
         exit 1