diff --git a/src/Illuminate/Contracts/Queue/UniqueJob.php b/src/Illuminate/Contracts/Queue/UniqueJob.php
deleted file mode 100644
index 603be95f5d42..000000000000
--- a/src/Illuminate/Contracts/Queue/UniqueJob.php
+++ /dev/null
@@ -1,8 +0,0 @@
-<?php
-
-namespace Illuminate\Contracts\Queue;
-
-interface UniqueJob
-{
-    //
-}
diff --git a/src/Illuminate/Foundation/Bus/PendingDispatch.php b/src/Illuminate/Foundation/Bus/PendingDispatch.php
index 98c36b3504b4..292856e82082 100644
--- a/src/Illuminate/Foundation/Bus/PendingDispatch.php
+++ b/src/Illuminate/Foundation/Bus/PendingDispatch.php
@@ -5,7 +5,6 @@
 use Illuminate\Container\Container;
 use Illuminate\Contracts\Bus\Dispatcher;
 use Illuminate\Contracts\Cache\Repository as Cache;
-use Illuminate\Contracts\Queue\UniqueJob;
 
 class PendingDispatch
 {
@@ -131,7 +130,8 @@ public function afterResponse()
      */
     protected function shouldDispatch()
     {
-        if (! ($this->job instanceof UniqueJob)) {
+        if (! method_exists($this->job, 'uniqueId')
+            && ! property_exists($this->job, 'uniqueId')) {
             return true;
         }
 
diff --git a/src/Illuminate/Foundation/Console/stubs/job.queued.stub b/src/Illuminate/Foundation/Console/stubs/job.queued.stub
index 0be12826fb73..5f0651cb1789 100644
--- a/src/Illuminate/Foundation/Console/stubs/job.queued.stub
+++ b/src/Illuminate/Foundation/Console/stubs/job.queued.stub
@@ -4,7 +4,6 @@ namespace {{ namespace }};
 
 use Illuminate\Bus\Queueable;
 use Illuminate\Contracts\Queue\ShouldQueue;
-use Illuminate\Contracts\Queue\UniqueJob;
 use Illuminate\Foundation\Bus\Dispatchable;
 use Illuminate\Queue\InteractsWithQueue;
 use Illuminate\Queue\SerializesModels;
diff --git a/src/Illuminate/Queue/CallQueuedHandler.php b/src/Illuminate/Queue/CallQueuedHandler.php
index ec3bfa48ea27..a3a653af25f8 100644
--- a/src/Illuminate/Queue/CallQueuedHandler.php
+++ b/src/Illuminate/Queue/CallQueuedHandler.php
@@ -8,7 +8,6 @@
 use Illuminate\Contracts\Cache\Repository as Cache;
 use Illuminate\Contracts\Container\Container;
 use Illuminate\Contracts\Queue\Job;
-use Illuminate\Contracts\Queue\UniqueJob;
 use Illuminate\Database\Eloquent\ModelNotFoundException;
 use Illuminate\Pipeline\Pipeline;
 use ReflectionClass;
@@ -167,7 +166,8 @@ protected function ensureSuccessfulBatchJobIsRecorded($command)
      */
     protected function ensureUniqueJobLockIsReleased($command)
     {
-        if ($command instanceof UniqueJob) {
+        if (method_exists($command, 'uniqueId')
+            || property_exists($command, 'uniqueId')) {
             $uniqueId = method_exists($command, 'uniqueId')
                         ? $command->uniqueId()
                         : ($command->uniqueId ?? '');
diff --git a/tests/Integration/Queue/UniqueJobTest.php b/tests/Integration/Queue/UniqueJobTest.php
index 45c09338ae40..8335e59199f7 100644
--- a/tests/Integration/Queue/UniqueJobTest.php
+++ b/tests/Integration/Queue/UniqueJobTest.php
@@ -5,7 +5,6 @@
 use Illuminate\Bus\Queueable;
 use Illuminate\Contracts\Cache\Repository as Cache;
 use Illuminate\Contracts\Queue\ShouldQueue;
-use Illuminate\Contracts\Queue\UniqueJob;
 use Illuminate\Database\Schema\Blueprint;
 use Illuminate\Foundation\Bus\Dispatchable;
 use Illuminate\Queue\InteractsWithQueue;
@@ -146,24 +145,28 @@ protected function getLockKey($job)
     }
 }
 
-class UniqueTestJob implements ShouldQueue, UniqueJob
+class UniqueTestJob implements ShouldQueue
 {
     use InteractsWithQueue, Queueable, Dispatchable;
 
     public static $handled = false;
 
+    public $uniqueId = '';
+
     public function handle()
     {
         static::$handled = true;
     }
 }
 
-class UniqueTestFailJob implements ShouldQueue, UniqueJob
+class UniqueTestFailJob implements ShouldQueue
 {
     use InteractsWithQueue, Queueable, Dispatchable;
 
     public $tries = 1;
 
+    public $uniqueId = '';
+
     public static $handled = false;
 
     public function handle()