diff --git a/src/Illuminate/Routing/CreatesRegularExpressionRouteConstraints.php b/src/Illuminate/Routing/CreatesRegularExpressionRouteConstraints.php
index e170451465c9..39744e9178bb 100644
--- a/src/Illuminate/Routing/CreatesRegularExpressionRouteConstraints.php
+++ b/src/Illuminate/Routing/CreatesRegularExpressionRouteConstraints.php
@@ -2,6 +2,7 @@
 
 namespace Illuminate\Routing;
 
+use BackedEnum;
 use Illuminate\Support\Arr;
 
 trait CreatesRegularExpressionRouteConstraints
@@ -70,7 +71,12 @@ public function whereUuid($parameters)
      */
     public function whereIn($parameters, array $values)
     {
-        return $this->assignExpressionToParameters($parameters, implode('|', $values));
+        return $this->assignExpressionToParameters(
+            $parameters, 
+            collect($values)
+                ->map(fn ($value) => $value instanceof BackedEnum ? $value->value : $value)
+                ->implode('|')
+        );
     }
 
     /**
diff --git a/tests/Routing/RouteRegistrarTest.php b/tests/Routing/RouteRegistrarTest.php
index 9171119f0741..cec7d2371131 100644
--- a/tests/Routing/RouteRegistrarTest.php
+++ b/tests/Routing/RouteRegistrarTest.php
@@ -12,6 +12,8 @@
 use PHPUnit\Framework\TestCase;
 use Stringable;
 
+include_once 'Enums.php';
+
 class RouteRegistrarTest extends TestCase
 {
     /**
@@ -942,6 +944,19 @@ public function testWhereInRegistration()
         }
     }
 
+    public function testWhereInEnumRegistration()
+    {
+        $this->router->get('/posts/{category}')->whereIn('category', CategoryBackedEnum::cases());
+
+        $invalidRequest = Request::create('/posts/invalid-value', 'GET');
+        $this->assertFalse($this->getRoute()->matches($invalidRequest));
+
+        foreach (CategoryBackedEnum::cases() as $case) {
+            $request = Request::create('/posts/'.$case->value, 'GET');
+            $this->assertTrue($this->getRoute()->matches($request));
+        }
+    }
+
     public function testGroupWhereNumberRegistrationOnRouteRegistrar()
     {
         $wheres = ['foo' => '[0-9]+', 'bar' => '[0-9]+'];