diff --git a/src/Illuminate/Routing/RoutingServiceProvider.php b/src/Illuminate/Routing/RoutingServiceProvider.php
index 0221839fc8df..aef743021378 100755
--- a/src/Illuminate/Routing/RoutingServiceProvider.php
+++ b/src/Illuminate/Routing/RoutingServiceProvider.php
@@ -137,10 +137,13 @@ protected function registerPsrRequest()
             if (class_exists(Psr17Factory::class) && class_exists(PsrHttpFactory::class)) {
                 $psr17Factory = new Psr17Factory;
 
-                return with((new PsrHttpFactory($psr17Factory, $psr17Factory, $psr17Factory, $psr17Factory))
-                    ->createRequest($illuminateRequest = $app->make('request')), fn ($request) => $request->withParsedBody(
-                        array_merge($request->getParsedBody(), $illuminateRequest->getPayload()->all())
-                    ));
+                return with(
+                    (new PsrHttpFactory($psr17Factory, $psr17Factory, $psr17Factory, $psr17Factory))
+                        ->createRequest($illuminateRequest = $app->make('request')),
+                    static fn ($request) => $request->withParsedBody(
+                        array_merge($request->getParsedBody() ?? [], $illuminateRequest->getPayload()->all())
+                    )
+                );
             }
 
             throw new BindingResolutionException('Unable to resolve PSR request. Please install the symfony/psr-http-message-bridge and nyholm/psr7 packages.');
diff --git a/tests/Integration/Foundation/RoutingServiceProviderTest.php b/tests/Integration/Foundation/RoutingServiceProviderTest.php
index 859b348eb774..c08526231879 100644
--- a/tests/Integration/Foundation/RoutingServiceProviderTest.php
+++ b/tests/Integration/Foundation/RoutingServiceProviderTest.php
@@ -26,6 +26,44 @@ public function testItIncludesMergedDataInServerRequestInterfaceInstancesUsingGe
         ]);
     }
 
+    public function testItWorksNormallyWithoutMergeDataMiddlewareWithEmptyRequests()
+    {
+        Route::get('test-route', function (ServerRequestInterface $request) {
+            return $request->getParsedBody();
+        });
+
+        $response = $this->withoutExceptionHandling()->get('test-route', [
+            'content-type' => 'application/json',
+        ]);
+
+        $response->assertOk();
+        $response->assertExactJson([]);
+    }
+
+    public function testItIncludesMergedDataInServerRequestInterfaceInstancesUsingGetJsonRequestsWithContentTypeHeader()
+    {
+        Route::get('test-route', function (ServerRequestInterface $request) {
+            return $request->getParsedBody();
+        })->middleware(MergeDataMiddleware::class);
+
+        $response = $this->getJson(
+            'test-route?' . http_build_query([
+                'sent' => 'sent-data',
+                'overridden' => 'overriden-sent-data',
+            ]), [
+                'content-type' => 'application/json',
+            ]
+        );
+
+        $response->assertOk();
+        $response->assertExactJson([
+            'json-data' => 'json-data',
+            'merged' => 'replaced-merged-data',
+            'overridden' => 'overriden-merged-data',
+            'request-data' => 'request-data',
+        ]);
+    }
+
     public function testItIncludesMergedDataInServerRequestInterfaceInstancesUsingGetJsonRequests()
     {
         Route::get('test-route', function (ServerRequestInterface $request) {