diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 1a116c06c..5b4709149 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -131,6 +131,12 @@ jobs:
       - uses: actions/checkout@v2
         with:
           submodules: recursive
+      - name: Cache runtime-tools
+        id: cache-runtime-tools
+        uses: actions/cache@v2
+        with:
+          path: integration_test
+          key: ${{ runner.os }}-${{ matrix.rust }}-primes
       - uses: actions-rs/toolchain@v1
         with:
           toolchain: ${{ matrix.rust }}