diff --git a/.github/workflows/condapackage.yml b/.github/workflows/condapackage.yml
index 8029d008..ea1296a5 100644
--- a/.github/workflows/condapackage.yml
+++ b/.github/workflows/condapackage.yml
@@ -22,6 +22,9 @@ jobs:
         $CONDA/bin/conda config --append channels conda-forge
         $CONDA/bin/conda config --append channels paulscherrerinstitute
 
+        $CONDA/bin/conda config --remove channels defaults
+        $CONDA/bin/conda config --system --remove channels defaults
+
         $CONDA/bin/conda config --show-sources
 
         $CONDA/bin/conda install --quiet conda-libmamba-solver