diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f8d16129b5..9d55e947ab 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -321,7 +321,7 @@ jobs:
         submodules: false
         fetch-depth: 1
     - name: Get CP deps
-      run: python tools/ci_fetch_deps.py ${{ matrix.board }} ${{ github.ref }}
+      run: python tools/ci_fetch_deps.py ${{ matrix.board }} ${{ github.sha }}
     - name: Install dependencies
       run: |
         sudo apt-get install -y gettext
@@ -373,7 +373,7 @@ jobs:
         submodules: false
         fetch-depth: 1
     - name: Get CP deps
-      run: python tools/ci_fetch_deps.py ${{ matrix.board }} ${{ github.ref }}
+      run: python tools/ci_fetch_deps.py ${{ matrix.board }} ${{ github.sha }}
     - name: CircuitPython version
       run: git describe --dirty --tags
     - uses: actions/cache@v2
@@ -460,7 +460,7 @@ jobs:
         submodules: false
         fetch-depth: 1
     - name: Get CP deps
-      run: python tools/ci_fetch_deps.py ${{ matrix.board }} ${{ github.ref }}
+      run: python tools/ci_fetch_deps.py ${{ matrix.board }} ${{ github.sha }}
     - name: Install dependencies
       run: |
         sudo apt-get install -y gettext mtools