diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ff67b6760..db71dca7b 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -24,6 +24,8 @@ jobs:
     - run: ./format -c
     - run: nix-shell --show-trace . -A install
     - run: yes | home-manager -I home-manager=. uninstall
-    - run: nix-shell --show-trace --arg enableBig false --pure tests -A run.all
+    - run: nix-shell -j auto --show-trace --arg enableBig false --pure tests -A run.all
       # Somebody please help us fix the macos tests.
       if: matrix.os != 'macos-latest'
+      env:
+        GC_INITIAL_HEAP_SIZE: 4294967296