diff --git a/system/Router/Router.php b/system/Router/Router.php
index f56af09c91f6..a72915acda72 100644
--- a/system/Router/Router.php
+++ b/system/Router/Router.php
@@ -542,6 +542,32 @@ public function autoRoute(string $uri)
 			$this->params = $segments;
 		}
 
+		if ($this->collection->getHTTPVerb() !== 'cli')
+		{
+			$controller  = '\\' . $this->collection->getDefaultNamespace();
+			$controller .= $this->directory ? str_replace('/', '\\', $this->directory) : '';
+			$controller .= $this->controllerName();
+			$controller  = strtolower($controller);
+			$methodName  = strtolower($this->methodName());
+
+			foreach ($this->collection->getRoutes('cli') as $route)
+			{
+				if (is_string($route))
+				{
+					$route = strtolower($route);
+					if (strpos($route, $controller . '::' . $methodName) === 0)
+					{
+						throw new PageNotFoundException();
+					}
+
+					if ($route === $controller)
+					{
+						throw new PageNotFoundException();
+					}
+				}
+			}
+		}
+
 		// Load the file so that it's available for CodeIgniter.
 		$file = APPPATH . 'Controllers/' . $this->directory . $this->controllerName() . '.php';
 		if (is_file($file))
diff --git a/tests/_support/Controllers/Hello.php b/tests/_support/Controllers/Hello.php
new file mode 100644
index 000000000000..8c7c05f01970
--- /dev/null
+++ b/tests/_support/Controllers/Hello.php
@@ -0,0 +1,11 @@
+<?php namespace App\Controllers;
+
+use CodeIgniter\Controller;
+
+class Hello extends Controller
+{
+	public function index()
+	{
+		return 'Hello';
+	}
+}
diff --git a/tests/system/Test/FeatureTestCaseTest.php b/tests/system/Test/FeatureTestCaseTest.php
index 52e4b0ee45a3..b89422760085 100644
--- a/tests/system/Test/FeatureTestCaseTest.php
+++ b/tests/system/Test/FeatureTestCaseTest.php
@@ -204,4 +204,54 @@ public function testCallZeroAsPathGot404()
 		}
 		$this->get('0');
 	}
+
+	public function provideRoutesData()
+	{
+		return [
+			'non parameterized cli'                => [
+				'hello',
+				'Hello::index',
+				'Hello',
+			],
+			'parameterized cli'                    => [
+				'hello/(:any)',
+				'Hello::index/$1',
+				'Hello/index/samsonasik',
+			],
+			'default method index'                 => [
+				'hello',
+				'Hello',
+				'Hello',
+			],
+			'capitalized controller and/or method' => [
+				'hello',
+				'Hello',
+				'HELLO/INDEX',
+			],
+		];
+	}
+
+	/**
+	 * @dataProvider provideRoutesData
+	 */
+	public function testOpenCliRoutesFromHttpGot404($from, $to, $httpGet)
+	{
+		$this->expectException(PageNotFoundException::class);
+
+		require_once SUPPORTPATH . 'Controllers/Hello.php';
+
+		$this->withRoutes([
+			[
+				'cli',
+				$from,
+				$to,
+			],
+		]);
+
+		while (\ob_get_level() > 0)
+		{
+			\ob_end_flush();
+		}
+		$this->get($httpGet);
+	}
 }