diff --git a/.github/workflows/gh-pages.yml b/.github/workflows/gh-pages.yml
index 0ef7bb1..36952c2 100644
--- a/.github/workflows/gh-pages.yml
+++ b/.github/workflows/gh-pages.yml
@@ -11,15 +11,26 @@ jobs:
     steps:
       - uses: actions/checkout@v2
 
+      - name: Set CURRENT_TWO_WEEKS for use in cache keys
+        run: echo "::set-env name=CURRENT_TWO_WEEKS::$(($(date +%V) / 2))"
+
       - name: Cache cargo registry
         uses: actions/cache@v1
         with:
           path: ~/.cargo/registry
+          key: ${{ runner.os }}-cargo-registry-${{ env.CURRENT_TWO_WEEKS }}
 
       - name: Cache cargo index
         uses: actions/cache@v1
         with:
           path: ~/.cargo/git
+          key: ${{ runner.os }}-cargo-index-${{ env.CURRENT_TWO_WEEKS }}
+
+      - name: Cache mdbook binary
+        uses: actions/cache@v1
+        with:
+          path: ~/.cargo/bin/mdbook
+          key: ${{ runner.os }}-cargo-mdbook-${{ env.CURRENT_TWO_WEEKS }}
 
       - name: Build mdbook
         run: cargo install mdbook