diff --git a/src/config.test.ts b/src/config.test.ts
index 8207101..265782f 100644
--- a/src/config.test.ts
+++ b/src/config.test.ts
@@ -479,6 +479,75 @@ describe("config", () => {
     expect(display.maxPlanRounds).toBe(2); // floored
   });
 
+  it("worker and timeout config defaults are applied", async () => {
+    const mod = await import("./config.js");
+
+    fs.mkdirSync(path.dirname(mod.CONFIG_PATH), { recursive: true });
+    fs.writeFileSync(mod.CONFIG_PATH, JSON.stringify({}));
+
+    const display = mod.getConfigForDisplay();
+    expect(display.maxClaudeWorkers).toBe(2);
+    expect(display.claudeTimeoutMs).toBe(20 * 60 * 1000);
+    expect(display.maxCopilotWorkers).toBe(1);
+    expect(display.copilotTimeoutMs).toBe(20 * 60 * 1000);
+    expect(display.maxCodexWorkers).toBe(1);
+    expect(display.codexTimeoutMs).toBe(20 * 60 * 1000);
+  });
+
+  it("worker counts clamp to 0 minimum", async () => {
+    const mod = await import("./config.js");
+
+    fs.mkdirSync(path.dirname(mod.CONFIG_PATH), { recursive: true });
+    fs.writeFileSync(mod.CONFIG_PATH, JSON.stringify({ maxClaudeWorkers: -1 }));
+
+    const display = mod.getConfigForDisplay();
+    expect(display.maxClaudeWorkers).toBe(0);
+  });
+
+  it("timeout values clamp to 60_000 minimum", async () => {
+    const mod = await import("./config.js");
+
+    fs.mkdirSync(path.dirname(mod.CONFIG_PATH), { recursive: true });
+    fs.writeFileSync(mod.CONFIG_PATH, JSON.stringify({ claudeTimeoutMs: 1000 }));
+
+    const display = mod.getConfigForDisplay();
+    expect(display.claudeTimeoutMs).toBe(60_000);
+  });
+
+  it("non-numeric worker/timeout values fall back to defaults", async () => {
+    const mod = await import("./config.js");
+
+    fs.mkdirSync(path.dirname(mod.CONFIG_PATH), { recursive: true });
+    fs.writeFileSync(mod.CONFIG_PATH, JSON.stringify({
+      maxClaudeWorkers: "bogus",
+      claudeTimeoutMs: "not-a-number",
+    }));
+
+    const display = mod.getConfigForDisplay();
+    expect(display.maxClaudeWorkers).toBe(2);
+    expect(display.claudeTimeoutMs).toBe(20 * 60 * 1000);
+  });
+
+  it("worker/timeout env vars override config file values", async () => {
+    process.env["YETI_MAX_CLAUDE_WORKERS"] = "5";
+    process.env["YETI_CLAUDE_TIMEOUT_MS"] = "300000";
+
+    const mod = await import("./config.js");
+
+    fs.mkdirSync(path.dirname(mod.CONFIG_PATH), { recursive: true });
+    fs.writeFileSync(mod.CONFIG_PATH, JSON.stringify({
+      maxClaudeWorkers: 2,
+      claudeTimeoutMs: 1200000,
+    }));
+
+    const display = mod.getConfigForDisplay();
+    expect(display.maxClaudeWorkers).toBe(5);
+    expect(display.claudeTimeoutMs).toBe(300000);
+
+    delete process.env["YETI_MAX_CLAUDE_WORKERS"];
+    delete process.env["YETI_CLAUDE_TIMEOUT_MS"];
+  });
+
   it("offConfigChange removes listener", async () => {
     const mod = await import("./config.js");
 
diff --git a/src/config.ts b/src/config.ts
index f06b309..37e992e 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -99,6 +99,13 @@ export interface ConfigFile {
   webhookSecret?: string;
 }
 
+/** Parse an integer from env var or config file value, with validation and optional minimum. */
+function parseIntConfig(envVal: string | undefined, fileVal: unknown, defaultVal: number, min?: number): number {
+  const parsed = parseInt(envVal ?? String(fileVal ?? defaultVal), 10);
+  if (!Number.isFinite(parsed)) return defaultVal;
+  return min !== undefined ? Math.max(min, parsed) : parsed;
+}
+
 function loadConfig() {
   let file: ConfigFile = {};
   try {
@@ -152,56 +159,12 @@ function loadConfig() {
   const authToken =
     process.env["YETI_AUTH_TOKEN"] ?? file.authToken ?? "";
 
-  const parsedMaxClaudeWorkers = parseInt(
-    process.env["YETI_MAX_CLAUDE_WORKERS"] ?? String(file.maxClaudeWorkers ?? 2),
-    10,
-  );
-  const maxClaudeWorkers =
-    Number.isFinite(parsedMaxClaudeWorkers) && parsedMaxClaudeWorkers >= 0
-      ? parsedMaxClaudeWorkers
-      : 2;
-
-  const parsedClaudeTimeoutMs = parseInt(
-    process.env["YETI_CLAUDE_TIMEOUT_MS"] ?? String(file.claudeTimeoutMs ?? 20 * 60 * 1000),
-    10,
-  );
-  const claudeTimeoutMs = Number.isFinite(parsedClaudeTimeoutMs)
-    ? Math.max(60_000, parsedClaudeTimeoutMs)
-    : 20 * 60 * 1000;
-
-  const parsedMaxCopilotWorkers = parseInt(
-    process.env["YETI_MAX_COPILOT_WORKERS"] ?? String(file.maxCopilotWorkers ?? 1),
-    10,
-  );
-  const maxCopilotWorkers =
-    Number.isFinite(parsedMaxCopilotWorkers) && parsedMaxCopilotWorkers >= 0
-      ? parsedMaxCopilotWorkers
-      : 1;
-
-  const parsedCopilotTimeoutMs = parseInt(
-    process.env["YETI_COPILOT_TIMEOUT_MS"] ?? String(file.copilotTimeoutMs ?? 20 * 60 * 1000),
-    10,
-  );
-  const copilotTimeoutMs = Number.isFinite(parsedCopilotTimeoutMs)
-    ? Math.max(60_000, parsedCopilotTimeoutMs)
-    : 20 * 60 * 1000;
-
-  const parsedMaxCodexWorkers = parseInt(
-    process.env["YETI_MAX_CODEX_WORKERS"] ?? String(file.maxCodexWorkers ?? 1),
-    10,
-  );
-  const maxCodexWorkers =
-    Number.isFinite(parsedMaxCodexWorkers) && parsedMaxCodexWorkers >= 0
-      ? parsedMaxCodexWorkers
-      : 1;
-
-  const parsedCodexTimeoutMs = parseInt(
-    process.env["YETI_CODEX_TIMEOUT_MS"] ?? String(file.codexTimeoutMs ?? 20 * 60 * 1000),
-    10,
-  );
-  const codexTimeoutMs = Number.isFinite(parsedCodexTimeoutMs)
-    ? Math.max(60_000, parsedCodexTimeoutMs)
-    : 20 * 60 * 1000;
+  const maxClaudeWorkers = parseIntConfig(process.env["YETI_MAX_CLAUDE_WORKERS"], file.maxClaudeWorkers, 2, 0);
+  const claudeTimeoutMs = parseIntConfig(process.env["YETI_CLAUDE_TIMEOUT_MS"], file.claudeTimeoutMs, 20 * 60 * 1000, 60_000);
+  const maxCopilotWorkers = parseIntConfig(process.env["YETI_MAX_COPILOT_WORKERS"], file.maxCopilotWorkers, 1, 0);
+  const copilotTimeoutMs = parseIntConfig(process.env["YETI_COPILOT_TIMEOUT_MS"], file.copilotTimeoutMs, 20 * 60 * 1000, 60_000);
+  const maxCodexWorkers = parseIntConfig(process.env["YETI_MAX_CODEX_WORKERS"], file.maxCodexWorkers, 1, 0);
+  const codexTimeoutMs = parseIntConfig(process.env["YETI_CODEX_TIMEOUT_MS"], file.codexTimeoutMs, 20 * 60 * 1000, 60_000);
 
   const envLogLevel = process.env["YETI_LOG_LEVEL"];
   const rawLogLevel = envLogLevel && (LOG_LEVELS as readonly string[]).includes(envLogLevel)