diff --git a/scripts/test-parallel.mjs b/scripts/test-parallel.mjs
index 242b444ff..8e3328aa5 100644
--- a/scripts/test-parallel.mjs
+++ b/scripts/test-parallel.mjs
@@ -37,6 +37,7 @@ const WARNING_SUPPRESSION_FLAGS = [
   "--disable-warning=ExperimentalWarning",
   "--disable-warning=DEP0040",
   "--disable-warning=DEP0060",
+  "--max-old-space-size=4096",
 ];
 
 const run = (entry) =>
@@ -54,6 +55,11 @@ const run = (entry) =>
     });
     children.add(child);
     child.on("exit", (code, signal) => {
+      if (signal === 'SIGKILL' || signal === 'SIGABRT' || signal === 'SIGSEGV') {
+        console.error(`Worker ${entry.name} crashed with signal ${signal} (possible OOM or resource exhaustion)`);
+      } else if (signal) {
+        console.warn(`Worker ${entry.name} terminated with signal ${signal}`);
+      }
       children.delete(child);
       resolve(code ?? (signal ? 1 : 0));
     });
diff --git a/vitest.config.ts b/vitest.config.ts
index 16c3b403a..358226c28 100644
--- a/vitest.config.ts
+++ b/vitest.config.ts
@@ -7,7 +7,7 @@ const repoRoot = path.dirname(fileURLToPath(import.meta.url));
 const isCI = process.env.CI === "true" || process.env.GITHUB_ACTIONS === "true";
 const isWindows = process.platform === "win32";
 const localWorkers = Math.max(4, Math.min(16, os.cpus().length));
-const ciWorkers = isWindows ? 2 : 3;
+const ciWorkers = isWindows ? 1 : 2;
 
 export default defineConfig({
   resolve: {
@@ -16,8 +16,8 @@ export default defineConfig({
     },
   },
   test: {
-    testTimeout: 120_000,
-    hookTimeout: isWindows ? 180_000 : 120_000,
+    testTimeout: 300_000,
+    hookTimeout: isWindows ? 300_000 : 240_000,
     pool: "forks",
     maxWorkers: isCI ? ciWorkers : localWorkers,
     include: [