diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d5db296..3daba03 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -64,6 +64,7 @@ jobs:
             --configfile="tests/test1/config-Ubuntu.yml" \
             --use-conda \
             --conda-create-envs-only \
+            --cores 1 \
             all
 
       # Run the tests sequentially;