diff --git a/gitlab/before_build.sh b/gitlab/before_build.sh
index 3adced1b514f90ec5d5913c8dd72e8ec4925824a..4dcc7dd4bcd8d01a5b63ccd118e8528a3f692f2b 100755
--- a/gitlab/before_build.sh
+++ b/gitlab/before_build.sh
@@ -32,6 +32,7 @@ set_conda_channels ${VISIBILITY} ${CI_COMMIT_TAG}
 for k in "${CONDA_CHANNELS[@]}"; do
   echo "  - ${DOCSERVER}/${k}" >> ${CONDARC}
 done
+echo "  - defaults" >> ${CONDARC}
 
 # displays contents of our configuration
 echo "Contents of \`${CONDARC}':"