diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9377d4b6fa..f3dbd1425a 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -83,10 +83,10 @@ jobs:
         run: msys2do ./script/ci.sh
         if: matrix.os == 'windows-latest'
       - name: Test
-        run: nix-shell --run "cd build; ctest -j --output-on-failure < /dev/null"
+        run: nix-shell --run "cd build; ctest -j4 --output-on-failure < /dev/null"
         if: matrix.os != 'windows-latest'
       - name: Test
-        run: msys2do cd build; ctest -j --output-on-failure ^< /dev/null
+        run: msys2do cd build; ctest -j4 --output-on-failure ^< /dev/null
         shell: cmd
         if: matrix.os == 'windows-latest'
       - name: Build Stage 2