diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 63019aa44..0b9e9c268 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -75,6 +75,7 @@ jobs:
         env:
           GROUP: All
           JULIA_NUM_THREADS: ${{ matrix.runner.num_threads }}
+          JULIA_NUM_GC_THREADS: '1'
 
       - uses: julia-actions/julia-processcoverage@v1