diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 182d66d6fc..20fa5fc99c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -452,7 +452,7 @@ jobs:
     timeout-minutes: 120
     env:
       DSH_COVERAGE_MAX_WORKERS: '6'
-      DSH_COVERAGE_PARTITIONS: '6'
+      DSH_COVERAGE_PARTITIONS: '4'
       DSH_COVERAGE_TEST_TIMEOUT_MS: '30000'
       DSH_GATE_CONCURRENCY: '3'
     steps:
diff --git a/scripts/ci-workflow.spec.ts b/scripts/ci-workflow.spec.ts
index 084e30c754..499d5a38d7 100644
--- a/scripts/ci-workflow.spec.ts
+++ b/scripts/ci-workflow.spec.ts
@@ -98,9 +98,9 @@ describe('CI workflow', () => {
     ))
     expect(buildCommands.map(step => step.run)).toContain('pnpm run check:ci:windows-blocking')
 
-    // windows-coverage runs the 6-partition profile.
+    // windows-coverage runs the 4-partition profile.
     expect(windowsCoverage.name).toBe('windows node 24 / coverage')
-    expect(windowsCoverage.env).toMatchObject({ DSH_COVERAGE_PARTITIONS: '6' })
+    expect(windowsCoverage.env).toMatchObject({ DSH_COVERAGE_PARTITIONS: '4' })
     const coverageSteps = windowsCoverage.steps as unknown[]
     const coverageCommands = coverageSteps.filter((step): step is Record<string, unknown> & { run: string } => (
       isRecord(step) && typeof step.run === 'string'