diff --git a/end2end/tests/express-mongodb.code-injection.test.js b/end2end/tests/express-mongodb.code-injection.test.js
new file mode 100644
index 000000000..0a41c0df5
--- /dev/null
+++ b/end2end/tests/express-mongodb.code-injection.test.js
@@ -0,0 +1,106 @@
+const t = require("tap");
+const { spawn } = require("child_process");
+const { resolve } = require("path");
+const timeout = require("../timeout");
+
+const pathToApp = resolve(
+  __dirname,
+  "../../sample-apps/express-mongodb",
+  "app.js"
+);
+
+t.setTimeout(60000);
+
+t.test("it blocks in blocking mode", (t) => {
+  const server = spawn(`node`, [pathToApp, "4000"], {
+    env: { ...process.env, AIKIDO_DEBUG: "true", AIKIDO_BLOCK: "true" },
+  });
+
+  server.on("close", () => {
+    t.end();
+  });
+
+  server.on("error", (err) => {
+    t.fail(err);
+  });
+
+  let stdout = "";
+  server.stdout.on("data", (data) => {
+    stdout += data.toString();
+  });
+
+  let stderr = "";
+  server.stderr.on("data", (data) => {
+    stderr += data.toString();
+  });
+
+  // Wait for the server to start
+  timeout(2000)
+    .then(() => {
+      return Promise.all([
+        fetch("http://127.0.0.1:4000/hello/hans", {
+          signal: AbortSignal.timeout(5000),
+        }),
+        fetch(`http://127.0.0.1:4000/hello/${encodeURIComponent(`hans" //`)}`, {
+          signal: AbortSignal.timeout(5000),
+        }),
+      ]);
+    })
+    .then(([safeName, unsafeName]) => {
+      t.equal(safeName.status, 200);
+      t.equal(unsafeName.status, 500);
+      t.match(stdout, /Starting agent/);
+      t.match(stdout, /Zen has blocked a JavaScript injection/);
+    })
+    .catch((error) => {
+      t.fail(error);
+    })
+    .finally(() => {
+      server.kill();
+    });
+});
+
+t.test("it does not block in dry mode", (t) => {
+  const server = spawn(`node`, [pathToApp, "4001"], {
+    env: { ...process.env, AIKIDO_DEBUG: "true" },
+  });
+
+  server.on("close", () => {
+    t.end();
+  });
+
+  let stdout = "";
+  server.stdout.on("data", (data) => {
+    stdout += data.toString();
+  });
+
+  let stderr = "";
+  server.stderr.on("data", (data) => {
+    stderr += data.toString();
+  });
+
+  // Wait for the server to start
+  timeout(2000)
+    .then(() =>
+      Promise.all([
+        fetch("http://127.0.0.1:4001/hello/hans", {
+          signal: AbortSignal.timeout(5000),
+        }),
+        fetch(`http://127.0.0.1:4001/hello/${encodeURIComponent(`hans" //`)}`, {
+          signal: AbortSignal.timeout(5000),
+        }),
+      ])
+    )
+    .then(([safeName, unsafeName]) => {
+      t.equal(safeName.status, 200);
+      t.equal(unsafeName.status, 200);
+      t.match(stdout, /Starting agent/);
+      t.match(stdout, /Zen has detected a JavaScript injection/);
+    })
+    .catch((error) => {
+      t.fail(error);
+    })
+    .finally(() => {
+      server.kill();
+    });
+});
diff --git a/end2end/tests/express-mongodb.test.js b/end2end/tests/express-mongodb.test.js
index 70c309fda..fed139393 100644
--- a/end2end/tests/express-mongodb.test.js
+++ b/end2end/tests/express-mongodb.test.js
@@ -21,7 +21,7 @@ t.test("it blocks in blocking mode", (t) => {
   });
 
   server.on("error", (err) => {
-    t.fail(err.message);
+    t.fail(err);
   });
 
   let stdout = "";
@@ -57,7 +57,7 @@ t.test("it blocks in blocking mode", (t) => {
       t.match(stderr, /Zen has blocked a NoSQL injection/);
     })
     .catch((error) => {
-      t.fail(error.message);
+      t.fail(error);
     })
     .finally(() => {
       server.kill();
@@ -106,7 +106,7 @@ t.test("it does not block in dry mode", (t) => {
       t.notMatch(stderr, /Zen has blocked a NoSQL injection/);
     })
     .catch((error) => {
-      t.fail(error.message);
+      t.fail(error);
     })
     .finally(() => {
       server.kill();
@@ -141,7 +141,7 @@ t.test("it blocks in blocking mode (with open telemetry enabled)", (t) => {
   });
 
   server.on("error", (err) => {
-    t.fail(err.message);
+    t.fail(err);
   });
 
   let stdout = "";
@@ -174,7 +174,7 @@ t.test("it blocks in blocking mode (with open telemetry enabled)", (t) => {
       t.match(stderr, /Zen has blocked a NoSQL injection/);
     })
     .catch((error) => {
-      t.fail(error.message);
+      t.fail(error);
     })
     .finally(() => {
       server.kill("SIGINT");
@@ -237,7 +237,7 @@ t.test("it does not block in dry mode (with open telemetry enabled)", (t) => {
       t.notMatch(stderr, /Zen has blocked a NoSQL injection/);
     })
     .catch((error) => {
-      t.fail(error.message);
+      t.fail(error);
     })
     .finally(() => {
       server.kill("SIGINT");
diff --git a/sample-apps/express-mongodb/app.js b/sample-apps/express-mongodb/app.js
index 0c318f0e4..b8234bc32 100644
--- a/sample-apps/express-mongodb/app.js
+++ b/sample-apps/express-mongodb/app.js
@@ -186,6 +186,24 @@ async function main(port) {
     })
   );
 
+  app.get(
+    "/hello/:name",
+    asyncHandler(async (req, res) => {
+      const { name } = req.params;
+
+      if (!name) {
+        return res.status(400).end();
+      }
+
+      // This code is vulnerable to code injection
+      // This is just a sample app to demonstrate the vulnerability
+      // Do not use this code in production
+      const welcome = new Function(`return "Hello, your name is ${name}!"`);
+
+      res.send(welcome());
+    })
+  );
+
   return new Promise((resolve, reject) => {
     try {
       app.listen(port, () => {