diff --git a/.github/workflows/build_slim_packages.yaml b/.github/workflows/build_slim_packages.yaml
index e0db564b8..7722d11a2 100644
--- a/.github/workflows/build_slim_packages.yaml
+++ b/.github/workflows/build_slim_packages.yaml
@@ -31,6 +31,11 @@ jobs:
         fi
     - name: fix-git-unsafe-repository
       run: git config --global --add safe.directory /__w/emqx/emqx
+    - uses: actions/cache@v2
+      with:
+        # dialyzer PLTs
+        path: ~/.cache/rebar3/
+        key: dialyer-${{ matrix.erl_otp }}
     - name: make xref
       run: make xref
     - name: make dialyzer