diff --git a/.github/workflows/ci-osx.yaml b/.github/workflows/ci-osx.yaml
index a62ffdfa..5e11791c 100644
--- a/.github/workflows/ci-osx.yaml
+++ b/.github/workflows/ci-osx.yaml
@@ -24,15 +24,27 @@ jobs:
         env:
             ACTIONS_ALLOW_UNSECURE_COMMANDS: true
 
+      - name: Show info about `base` environment
+        shell: "bash -l {0}"
+        run: |
+          conda info
+          conda config --show-sources
+          conda list --show-channel-urls
+
       - name: Set up env
         shell: "bash -l {0}"
         run: |
-          conda create -n env python==${{matrix.python-version}} wheel pip compilers
+          conda create -n env python=${{matrix.python-version}} wheel pip compilers 'clang>=12.0.1'
           conda activate env
           which pip
           pip install -r requirements_test.txt -r requirements.txt
           conda env export
 
+      - name: Show info about `env` environment
+        shell: "bash -l {0}"
+        run: |
+          conda list --show-channel-urls -n env
+
       - name: Install numcodecs
         shell: "bash -l {0}"
         run: |
diff --git a/.github/workflows/ci-windows.yaml b/.github/workflows/ci-windows.yaml
index 487fcb45..8f38b3ec 100644
--- a/.github/workflows/ci-windows.yaml
+++ b/.github/workflows/ci-windows.yaml
@@ -27,7 +27,7 @@ jobs:
       - name: Set up env
         shell: "bash -l {0}"
         run: |
-          conda create -n env python==${{matrix.python-version}} wheel pip compilers
+          conda create -n env python=${{matrix.python-version}} wheel pip compilers
           conda activate env
           which pip
           pip install -r requirements_test.txt -r requirements.txt