diff --git a/.github/workflows/test-slow.yml b/.github/workflows/test-slow.yml
index c40a174..8498053 100644
--- a/.github/workflows/test-slow.yml
+++ b/.github/workflows/test-slow.yml
@@ -7,6 +7,8 @@ jobs:
   dos:
     name: Test for DoS
     runs-on: ubuntu-latest
+    env:
+      MSHOULD_FAST: '1'
     steps:
       - uses: actions/checkout@1e31de5234b9f8995739874a8ce0492dc87873e2 # v4
       - name: Use Node.js ${{ matrix.node }}
@@ -17,10 +19,12 @@ jobs:
           cache: npm
       - run: npm install
       - run: npm run build --if-present
-      - run: npm test:dos
+      - run: npm run test:dos
   big:
     name: Test large inputs & slow KDFs
     runs-on: ubuntu-latest
+    env:
+      MSHOULD_FAST: '1'
     steps:
       - uses: actions/checkout@1e31de5234b9f8995739874a8ce0492dc87873e2 # v4
       - name: Use Node.js ${{ matrix.node }}
@@ -31,4 +35,4 @@ jobs:
           cache: npm
       - run: npm install
       - run: npm run build --if-present
-      - run: npm test:big
+      - run: npm run test:big