diff --git a/src/Illuminate/Queue/Middleware/WithoutOverlapping.php b/src/Illuminate/Queue/Middleware/WithoutOverlapping.php
index 19b4c27fb6f2..17ed75e6feb6 100644
--- a/src/Illuminate/Queue/Middleware/WithoutOverlapping.php
+++ b/src/Illuminate/Queue/Middleware/WithoutOverlapping.php
@@ -6,6 +6,8 @@
 use Illuminate\Contracts\Cache\Repository as Cache;
 use Illuminate\Support\InteractsWithTime;
 
+use function Illuminate\Support\enum_value;
+
 class WithoutOverlapping
 {
     use InteractsWithTime;
@@ -48,13 +50,13 @@ class WithoutOverlapping
     /**
      * Create a new middleware instance.
      *
-     * @param  string  $key
+     * @param  \UnitEnum|string  $key
      * @param  \DateTimeInterface|int|null  $releaseAfter
      * @param  \DateTimeInterface|int  $expiresAfter
      */
     public function __construct($key = '', $releaseAfter = 0, $expiresAfter = 0)
     {
-        $this->key = $key;
+        $this->key = enum_value($key);
         $this->releaseAfter = $releaseAfter;
         $this->expiresAfter = $this->secondsUntil($expiresAfter);
     }
diff --git a/tests/Integration/Queue/WithoutOverlappingJobsTest.php b/tests/Integration/Queue/WithoutOverlappingJobsTest.php
index a69c2df87e39..8f3f85f8a1eb 100644
--- a/tests/Integration/Queue/WithoutOverlappingJobsTest.php
+++ b/tests/Integration/Queue/WithoutOverlappingJobsTest.php
@@ -175,6 +175,26 @@ public function testGetLockUsesDisplayName()
             'prefix:key',
             (new WithoutOverlapping('key'))->withPrefix('prefix:')->shared()->getLockKey($job)
         );
+
+        $this->assertSame(
+            'prefix:'.hash('xxh128', 'App\\Actions\\WithoutOverlappingTestAction').':unit',
+            (new WithoutOverlapping(UnitCategory::unit))->withPrefix('prefix:')->getLockKey($job)
+        );
+
+        $this->assertSame(
+            'prefix:unit',
+            (new WithoutOverlapping(UnitCategory::unit))->withPrefix('prefix:')->shared()->getLockKey($job)
+        );
+
+        $this->assertSame(
+            'prefix:'.hash('xxh128', 'App\\Actions\\WithoutOverlappingTestAction').':backed',
+            (new WithoutOverlapping(BackedCategory::backed))->withPrefix('prefix:')->getLockKey($job)
+        );
+
+        $this->assertSame(
+            'prefix:backed',
+            (new WithoutOverlapping(BackedCategory::backed))->withPrefix('prefix:')->shared()->getLockKey($job)
+        );
     }
 }
 
@@ -254,3 +274,13 @@ public function displayName(): string
         return 'App\\Actions\\WithoutOverlappingTestAction';
     }
 }
+
+enum UnitCategory
+{
+    case unit;
+}
+
+enum BackedCategory: string
+{
+    case backed = 'backed';
+}