diff --git a/.github/workflows/test-wheel-linux.yml b/.github/workflows/test-wheel-linux.yml
index 3b7761fe4e..4f417b6a81 100644
--- a/.github/workflows/test-wheel-linux.yml
+++ b/.github/workflows/test-wheel-linux.yml
@@ -269,17 +269,15 @@ jobs:
       - name: Ensure cuda-python installable
         run: |
           if [[ "${{ matrix.LOCAL_CTK }}" == 1 ]]; then
-            pip install cuda_python*.whl
+            pip install --only-binary=:all: cuda_python*.whl
           else
-            pip install $(ls cuda_python*.whl)[all]
+            pip install --only-binary=:all: $(ls cuda_python*.whl)[all]
           fi
 
       - name: Install cuda.pathfinder extra wheels for testing
         run: |
           set -euo pipefail
           pushd cuda_pathfinder
-          # Install pathfinder from the pre-built wheel, since building from
-          # source won't work in this context (we don't have a git checkout).
           pip install --only-binary=:all: -v ./*.whl --group "test-cu${TEST_CUDA_MAJOR}"
           pip list
           popd
diff --git a/.github/workflows/test-wheel-windows.yml b/.github/workflows/test-wheel-windows.yml
index e9c20a625c..eaabdf47d0 100644
--- a/.github/workflows/test-wheel-windows.yml
+++ b/.github/workflows/test-wheel-windows.yml
@@ -236,16 +236,16 @@ jobs:
       - name: Ensure cuda-python installable
         run: |
           if ('${{ matrix.LOCAL_CTK }}' -eq '1') {
-            pip install (Get-ChildItem -Filter cuda_python*.whl).FullName
+            pip install --only-binary=:all: (Get-ChildItem -Filter cuda_python*.whl).FullName
           } else {
-            pip install "$((Get-ChildItem -Filter cuda_python*.whl).FullName)[all]"
+            pip install --only-binary=:all: "$((Get-ChildItem -Filter cuda_python*.whl).FullName)[all]"
           }
 
       - name: Install cuda.pathfinder extra wheels for testing
         shell: bash --noprofile --norc -xeuo pipefail {0}
         run: |
           pushd cuda_pathfinder
-          pip install --only-binary=:all: -v . --group "test-cu${TEST_CUDA_MAJOR}"
+          pip install --only-binary=:all: -v ./*.whl --group "test-cu${TEST_CUDA_MAJOR}"
           pip list
           popd