diff --git a/README.md b/README.md
index 095e3ec..c24d939 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ After install, set your credentials from [TestingBot account settings](https://t
 
 ## Prerequisites
 
-- **Node.js** >= 18 (recommended: 22.15.0 or later)
+- **Node.js** >= 20 (recommended: 22.15.0 or later)
 - **TestingBot Account** with API credentials
 - An MCP-compatible client (Claude Desktop, VS Code with Continue, Cursor, etc.)
 
@@ -856,7 +856,7 @@ If you see authentication errors:
 If the MCP server won't connect:
 1. Restart your MCP client (Claude Desktop, VS Code, etc.)
 2. Check the MCP client logs for errors
-3. Verify Node.js version is >= 18
+3. Verify Node.js version is >= 20
 
 ### Tool Execution Errors
 
diff --git a/package.json b/package.json
index 241d5a6..aa5b8ea 100644
--- a/package.json
+++ b/package.json
@@ -35,7 +35,7 @@
     "LICENSE"
   ],
   "engines": {
-    "node": ">=18"
+    "node": ">=20"
   },
   "keywords": [
     "mcp",
diff --git a/src/server-factory.ts b/src/server-factory.ts
index 13954aa..eefa397 100644
--- a/src/server-factory.ts
+++ b/src/server-factory.ts
@@ -213,7 +213,9 @@ export class TestingBotMcpServer {
   // traffic. Throws on any blocking issue so the entry point can exit with a
   // clear error instead of letting the first tool call fail mysteriously.
   public async preflight(): Promise<void> {
-    const required = 18;
+    // Must match `engines.node` in package.json, and the floor enforced by
+    // @testingbot/automation-mcp, which hard-fails its own preflight below 20.
+    const required = 20;
     const major = Number(process.versions.node.split(".")[0]);
     if (!Number.isFinite(major) || major < required) {
       throw new Error(
diff --git a/tests/server-factory.test.ts b/tests/server-factory.test.ts
index f4f729e..c6e050e 100644
--- a/tests/server-factory.test.ts
+++ b/tests/server-factory.test.ts
@@ -40,10 +40,18 @@ describe("TestingBotMcpServer.preflight", () => {
   it("rejects unsupported Node versions before hitting the API", async () => {
     setNodeVersion("16.20.0");
     const server = new TestingBotMcpServer(testingBotApiMock, configMock);
-    await expect(server.preflight()).rejects.toThrow(/Node.js 18\+ is required/);
+    await expect(server.preflight()).rejects.toThrow(/Node.js 20\+ is required/);
     expect(testingBotApiMock.getUserInfo).not.toHaveBeenCalled();
   });
 
+  it("rejects Node 18, which @testingbot/automation-mcp no longer supports", async () => {
+    // The bundled automation tools hard-fail their own preflight below 20, so
+    // accepting 18 here would install cleanly and then die at startup.
+    setNodeVersion("18.20.0");
+    const server = new TestingBotMcpServer(testingBotApiMock, configMock);
+    await expect(server.preflight()).rejects.toThrow(/Node.js 20\+ is required/);
+  });
+
   it("starts in degraded mode (no throw) when api_key is missing", async () => {
     setNodeVersion("20.10.0");
     const server = new TestingBotMcpServer(testingBotApiMock, {