diff --git a/.github/workflows/test-gb-25.yml b/.github/workflows/test-gb-25.yml
index 70ce23af4c..d191690d2e 100644
--- a/.github/workflows/test-gb-25.yml
+++ b/.github/workflows/test-gb-25.yml
@@ -187,7 +187,7 @@ jobs:
         timeout-minutes: 60
         run: |
           export XLA_FLAGS='--xla_dump_to=${{ env.GB25_DIR }}/xla_dump'
-          timeout --signal=TERM --verbose 59m mpiexecjl -np 1 julia --color=yes --project -O0 --startup-file=no --threads=16 --compiled-modules=strict sharding/sharded_baroclinic_instability_simulation_run.jl
+          timeout --signal=TERM --verbose 59m mpiexecjl -np 1 julia --color=yes --project -O0 --startup-file=no --threads=16 --compiled-modules=strict sharding/sharded_baroclinic_instability_simulation_run.jl --grid-x=6144 --grid-y=1536 --grid-z=4
         working-directory: ${{ env.GB25_DIR }}
       - name: Test correctness in GB-25 code
         timeout-minutes: 20