diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 11a634389e..dfed301f55 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -104,151 +104,147 @@ jobs:
         run: cabal build
 
       - name: Set test options
-        # run the tests without parallelism, otherwise tasty will attempt to run
-        # all functional test cases simultaneously which causes way too many hls
-        # instances to be spun up for the poor github actions runner to handle
-        #
         # See https://github.com/ocharles/tasty-rerun/issues/22 for why we need
         # to include 'new' in the filters, since many of our test suites are in the
         # same package.
         run: |
-          echo "TEST_OPTS=-j1 --rerun-update --rerun-filter failures,exceptions,new" >> $GITHUB_ENV
+          cabal configure --test-options="--rerun-update --rerun-filter failures,exceptions,new"
 
       - if: matrix.test
         name: Test hls-graph
-        run: cabal test hls-graph --test-options="$TEST_OPTS"
+        run: cabal test hls-graph 
 
       - if: needs.pre_job.outputs.should_skip_ghcide != 'true' && matrix.test
         name: Test ghcide
         # run the tests without parallelism to avoid running out of memory
-        run: cabal test ghcide --test-options="$TEST_OPTS" || cabal test ghcide --test-options="$TEST_OPTS"
+        run: cabal test ghcide || cabal test ghcide 
 
       - if: matrix.test
         name: Test hls-plugin-api
-        run: cabal test hls-plugin-api --test-options="$TEST_OPTS" || cabal test hls-plugin-api --test-options="$TEST_OPTS"
+        run: cabal test hls-plugin-api || cabal test hls-plugin-api 
 
       - if: matrix.test
         name: Test func-test suite
         env:
           HLS_TEST_EXE: hls
           HLS_WRAPPER_TEST_EXE: hls-wrapper
-        run: cabal test func-test --test-options="$TEST_OPTS" || cabal test func-test --test-options="$TEST_OPTS"
+        run: cabal test func-test || cabal test func-test 
 
       - if: matrix.test
         name: Test wrapper-test suite
         env:
           HLS_TEST_EXE: hls
           HLS_WRAPPER_TEST_EXE: hls-wrapper
-        run: cabal test wrapper-test --test-options="$TEST_OPTS --rerun-log-file .tasty-rerun-log-wrapper"
+        run: cabal test wrapper-test 
 
       - if: matrix.test
         name: Test hls-refactor-plugin
-        run: cabal test hls-refactor-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-refactor-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-refactor-plugin-tests || cabal test hls-refactor-plugin-tests 
 
       - if: matrix.test 
         name: Test hls-floskell-plugin
-        run: cabal test hls-floskell-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-floskell-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-floskell-plugin-tests || cabal test hls-floskell-plugin-tests 
 
       - if: matrix.test
         name: Test hls-class-plugin
-        run: cabal test hls-class-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-class-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-class-plugin-tests || cabal test hls-class-plugin-tests 
 
       - if: matrix.test
         name: Test hls-pragmas-plugin
-        run: cabal test hls-pragmas-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-pragmas-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-pragmas-plugin-tests || cabal test hls-pragmas-plugin-tests 
 
       - if: matrix.test
         name: Test hls-eval-plugin
-        run: cabal test hls-eval-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-eval-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-eval-plugin-tests || cabal test hls-eval-plugin-tests 
 
       - if: matrix.test
         name: Test hls-splice-plugin
-        run: cabal test hls-splice-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-splice-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-splice-plugin-tests || cabal test hls-splice-plugin-tests 
 
       - if: matrix.test && matrix.ghc != '9.2'
         name: Test hls-stan-plugin
-        run: cabal test hls-stan-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-stan-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-stan-plugin-tests || cabal test hls-stan-plugin-tests 
 
       - if: matrix.test
         name: Test hls-stylish-haskell-plugin
-        run: cabal test hls-stylish-haskell-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-stylish-haskell-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-stylish-haskell-plugin-tests || cabal test hls-stylish-haskell-plugin-tests 
 
       - if: matrix.test 
         name: Test hls-ormolu-plugin
-        run: cabal test hls-ormolu-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-ormolu-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-ormolu-plugin-tests || cabal test hls-ormolu-plugin-tests 
 
       - if: matrix.test 
         name: Test hls-fourmolu-plugin
-        run: cabal test hls-fourmolu-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-fourmolu-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-fourmolu-plugin-tests || cabal test hls-fourmolu-plugin-tests 
 
       - if: matrix.test
         name: Test hls-explicit-imports-plugin test suite
-        run: cabal test hls-explicit-imports-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-explicit-imports-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-explicit-imports-plugin-tests || cabal test hls-explicit-imports-plugin-tests 
 
       - if: matrix.test
         name: Test hls-call-hierarchy-plugin test suite
-        run: cabal test hls-call-hierarchy-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-call-hierarchy-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-call-hierarchy-plugin-tests || cabal test hls-call-hierarchy-plugin-tests 
 
       - if: matrix.test && matrix.os != 'windows-latest'
         name: Test hls-rename-plugin test suite
-        run: cabal test hls-rename-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-rename-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-rename-plugin-tests || cabal test hls-rename-plugin-tests 
 
       - if: matrix.test 
         name: Test hls-hlint-plugin test suite
-        run: cabal test hls-hlint-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-hlint-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-hlint-plugin-tests || cabal test hls-hlint-plugin-tests 
 
       - if: matrix.test
         name: Test hls-module-name-plugin test suite
-        run: cabal test hls-module-name-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-module-name-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-module-name-plugin-tests || cabal test hls-module-name-plugin-tests 
 
       - if: matrix.test
         name: Test hls-alternate-number-format-plugin test suite
-        run: cabal test hls-alternate-number-format-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-alternate-number-format-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-alternate-number-format-plugin-tests || cabal test hls-alternate-number-format-plugin-tests 
 
       - if: matrix.test
         name: Test hls-qualify-imported-names-plugin test suite
-        run: cabal test hls-qualify-imported-names-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-qualify-imported-names-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-qualify-imported-names-plugin-tests || cabal test hls-qualify-imported-names-plugin-tests 
 
       - if: matrix.test
         name: Test hls-code-range-plugin test suite
-        run: cabal test hls-code-range-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-code-range-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-code-range-plugin-tests || cabal test hls-code-range-plugin-tests 
 
       - if: matrix.test
         name: Test hls-change-type-signature test suite
-        run: cabal test hls-change-type-signature-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-change-type-signature-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-change-type-signature-plugin-tests || cabal test hls-change-type-signature-plugin-tests 
 
       - if: matrix.test
         name: Test hls-gadt-plugin test suit
-        run: cabal test hls-gadt-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-gadt-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-gadt-plugin-tests || cabal test hls-gadt-plugin-tests 
 
       - if: matrix.test
         name: Test hls-explicit-fixity-plugin test suite
-        run: cabal test hls-explicit-fixity-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-explicit-fixity-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-explicit-fixity-plugin-tests || cabal test hls-explicit-fixity-plugin-tests 
 
       - if: matrix.test
         name: Test hls-explicit-record-fields-plugin test suite
-        run: cabal test hls-explicit-record-fields-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-explicit-record-fields-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-explicit-record-fields-plugin-tests || cabal test hls-explicit-record-fields-plugin-tests 
 
       ## version needs to be limited since the tests depend on cabal-fmt which only builds using specific ghc versions
       - if: matrix.test && matrix.ghc == '9.2'
         name: Test hls-cabal-fmt-plugin test suite
-        run: cabal test hls-cabal-fmt-plugin-tests --flag=isolateCabalfmtTests --test-options="$TEST_OPTS" || cabal test hls-cabal-fmt-plugin-tests --flag=isolateCabalfmtTests --test-options="$TEST_OPTS"
+        run: cabal test hls-cabal-fmt-plugin-tests --flag=isolateCabalfmtTests || cabal test hls-cabal-fmt-plugin-tests --flag=isolateCabalfmtTests 
 
       - if: matrix.test
         name: Test hls-cabal-plugin test suite
-        run: cabal test hls-cabal-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-cabal-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-cabal-plugin-tests || cabal test hls-cabal-plugin-tests 
 
       - if: matrix.test
         name: Test hls-retrie-plugin test suite
-        run: cabal test hls-retrie-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-retrie-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-retrie-plugin-tests || cabal test hls-retrie-plugin-tests 
 
       - if: matrix.test
         name: Test hls-overloaded-record-dot-plugin test suite
-        run: cabal test hls-overloaded-record-dot-plugin-tests --test-options="$TEST_OPTS" || LSP_TEST_LOG_COLOR=0 LSP_TEST_LOG_MESSAGES=true LSP_TEST_LOG_STDERR=true cabal test hls-overloaded-record-dot-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-overloaded-record-dot-plugin-tests || cabal test hls-overloaded-record-dot-plugin-tests 
 
       - if: matrix.test
         name: Test hls-semantic-tokens-plugin test suite
-        run: cabal test hls-semantic-tokens-plugin-tests --test-options="$TEST_OPTS" || cabal test hls-semantic-tokens-plugin-tests --test-options="$TEST_OPTS"
+        run: cabal test hls-semantic-tokens-plugin-tests || cabal test hls-semantic-tokens-plugin-tests 
 
 
   test_post_job:
diff --git a/cabal.project b/cabal.project
index adf19ed228..dd45e316e3 100644
--- a/cabal.project
+++ b/cabal.project
@@ -18,6 +18,11 @@ benchmarks: True
 
 write-ghc-environment-files: never
 
+-- Many of our tests only work single-threaded, and the only way to
+-- ensure tasty runs everything purely single-threaded is to pass 
+-- this at the top-level
+test-options: -j1
+
 -- Make sure dependencies are build with haddock so we get
 -- haddock shown on hover
 package *
diff --git a/hls-test-utils/src/Test/Hls.hs b/hls-test-utils/src/Test/Hls.hs
index a9fc31ef71..17fb48ff99 100644
--- a/hls-test-utils/src/Test/Hls.hs
+++ b/hls-test-utils/src/Test/Hls.hs
@@ -122,7 +122,6 @@ import           Test.Tasty.ExpectedFailure
 import           Test.Tasty.Golden
 import           Test.Tasty.HUnit
 import           Test.Tasty.Ingredients.Rerun
-import           Test.Tasty.Runners                 (NumThreads (..))
 
 data Log
   = LogIDEMain IDEMain.Log
@@ -147,7 +146,7 @@ instance Pretty LogTestHarness where
 
 -- | Run 'defaultMainWithRerun', limiting each single test case running at most 10 minutes
 defaultTestRunner :: TestTree -> IO ()
-defaultTestRunner = defaultMainWithRerun . adjustOption (const $ NumThreads 1) . adjustOption (const $ mkTimeout 600000000)
+defaultTestRunner = defaultMainWithRerun . adjustOption (const $ mkTimeout 600000000)
 
 gitDiff :: FilePath -> FilePath -> [String]
 gitDiff fRef fNew = ["git", "-c", "core.fileMode=false", "diff", "--no-index", "--text", "--exit-code", fRef, fNew]