diff --git a/.github/workflows/conda-build.yml b/.github/workflows/conda-build.yml
index 6b104218..b71cadb7 100644
--- a/.github/workflows/conda-build.yml
+++ b/.github/workflows/conda-build.yml
@@ -37,7 +37,7 @@ jobs:
           channels: conda-forge,bioconda,tpeulen,defaults
           channel-priority: true
         env:
-          CONDA_SUBDIR: ${{ matrix.os == 'macos-latest' && 'osx-64' }}
+          CONDA_SUBDIR: ${{ matrix.os == 'macos-latest' && 'osx-64' || null }}
 
       - name: Display Conda Settings
         shell: bash -el {0}
diff --git a/.github/workflows/conda-release.yml b/.github/workflows/conda-release.yml
index cd6b1cc3..0993e55c 100644
--- a/.github/workflows/conda-release.yml
+++ b/.github/workflows/conda-release.yml
@@ -35,7 +35,7 @@ jobs:
           channels: conda-forge,bioconda,tpeulen,defaults
           channel-priority: true
         env:
-          CONDA_SUBDIR: ${{ matrix.os == 'macos-latest' && 'osx-64' }}
+          CONDA_SUBDIR: ${{ matrix.os == 'macos-latest' && 'osx-64' || null }}
 
       - name: Display Conda Settings
         shell: bash -el {0}