diff --git a/src/Illuminate/Foundation/Testing/Concerns/InteractsWithDatabase.php b/src/Illuminate/Foundation/Testing/Concerns/InteractsWithDatabase.php
index f216a15c1e30..0b47714d1414 100644
--- a/src/Illuminate/Foundation/Testing/Concerns/InteractsWithDatabase.php
+++ b/src/Illuminate/Foundation/Testing/Concerns/InteractsWithDatabase.php
@@ -231,9 +231,10 @@ protected function isSoftDeletableModel($model)
      * Cast a JSON string to a database compatible type.
      *
      * @param  array|object|string  $value
+     * @param  string|null  $collection
      * @return \Illuminate\Contracts\Database\Query\Expression
      */
-    public function castAsJson($value)
+    public function castAsJson($value, $connection = null)
     {
         if ($value instanceof Jsonable) {
             $value = $value->toJson();
@@ -241,10 +242,12 @@ public function castAsJson($value)
             $value = json_encode($value);
         }
 
-        $value = DB::connection()->getPdo()->quote($value);
+        $db = DB::connection($connection);
 
-        return DB::raw(
-            DB::connection()->getQueryGrammar()->compileJsonValueCast($value)
+        $value = $db->getPdo()->quote($value);
+
+        return $db->raw(
+            $db->getQueryGrammar()->compileJsonValueCast($value)
         );
     }
 
diff --git a/tests/Testing/Concerns/InteractsWithDatabaseTest.php b/tests/Testing/Concerns/InteractsWithDatabaseTest.php
index 497653645292..9b9168930c61 100644
--- a/tests/Testing/Concerns/InteractsWithDatabaseTest.php
+++ b/tests/Testing/Concerns/InteractsWithDatabaseTest.php
@@ -149,15 +149,15 @@ protected function castAsJson($value, $grammar)
 
         $connection->shouldReceive('getQueryGrammar')->andReturn($grammar);
 
+        $connection->shouldReceive('raw')->andReturnUsing(function ($value) {
+            return new Expression($value);
+        });
+
         $connection->shouldReceive('getPdo->quote')->andReturnUsing(function ($value) {
             return "'".$value."'";
         });
 
-        DB::shouldReceive('connection')->andReturn($connection);
-
-        DB::shouldReceive('raw')->andReturnUsing(function ($value) {
-            return new Expression($value);
-        });
+        DB::shouldReceive('connection')->with(null)->andReturn($connection);
 
         $instance = new class
         {