diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6c84644b1..ed3ec735d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -41,6 +41,7 @@ Docs: https://docs.clawd.bot
 - Google Chat: tighten email allowlist matching, typing cleanup, media caps, and onboarding/docs/tests. (#1635) Thanks @iHildy.
 - Google Chat: normalize space targets without double `spaces/` prefix.
 - Messaging: keep newline chunking safe for fenced markdown blocks across channels.
+- Tests: cap Vitest workers to reduce CI timeouts, especially on macOS.
 
 ## 2026.1.23-1
 
diff --git a/scripts/test-parallel.mjs b/scripts/test-parallel.mjs
index d1c4871b1..e88cb2024 100644
--- a/scripts/test-parallel.mjs
+++ b/scripts/test-parallel.mjs
@@ -22,12 +22,13 @@ const parallelRuns = runs.filter((entry) => entry.name !== "gateway");
 const serialRuns = runs.filter((entry) => entry.name === "gateway");
 
 const children = new Set();
-const isCI = process.env.CI === "true" || process.env.GITHUB_ACTIONS === "true";
 const overrideWorkers = Number.parseInt(process.env.CLAWDBOT_TEST_WORKERS ?? "", 10);
 const resolvedOverride = Number.isFinite(overrideWorkers) && overrideWorkers > 0 ? overrideWorkers : null;
 const localWorkers = Math.max(4, Math.min(16, os.cpus().length));
 const perRunWorkers = Math.max(1, Math.floor(localWorkers / parallelRuns.length));
-const maxWorkers = isCI ? null : resolvedOverride ?? perRunWorkers;
+// Keep worker counts predictable across local runs and CI (avoid oversubscribing runners).
+// Total workers ~= localWorkers since we run unit/extensions in parallel.
+const maxWorkers = resolvedOverride ?? perRunWorkers;
 
 const WARNING_SUPPRESSION_FLAGS = [
   "--disable-warning=ExperimentalWarning",