diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index e1f39142..1cd07aec 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -640,6 +640,26 @@ parameters:
 			count: 1
 			path: tests/Database/SelectFields/QueryArgsAndContextTests/UsersQuery.php
 
+		-
+			message: "#^Method Rebing\\\\GraphQL\\\\Tests\\\\Database\\\\SelectFields\\\\UnionTests\\\\SearchQuery\\:\\:resolve\\(\\) has no return type specified\\.$#"
+			count: 1
+			path: tests/Database/SelectFields/UnionTests/SearchQuery.php
+
+		-
+			message: "#^Method Rebing\\\\GraphQL\\\\Tests\\\\Database\\\\SelectFields\\\\UnionTests\\\\SearchQuery\\:\\:resolve\\(\\) has parameter \\$args with no type specified\\.$#"
+			count: 1
+			path: tests/Database/SelectFields/UnionTests/SearchQuery.php
+
+		-
+			message: "#^Method Rebing\\\\GraphQL\\\\Tests\\\\Database\\\\SelectFields\\\\UnionTests\\\\SearchQuery\\:\\:resolve\\(\\) has parameter \\$ctx with no type specified\\.$#"
+			count: 1
+			path: tests/Database/SelectFields/UnionTests/SearchQuery.php
+
+		-
+			message: "#^Method Rebing\\\\GraphQL\\\\Tests\\\\Database\\\\SelectFields\\\\UnionTests\\\\SearchQuery\\:\\:resolve\\(\\) has parameter \\$root with no type specified\\.$#"
+			count: 1
+			path: tests/Database/SelectFields/UnionTests/SearchQuery.php
+
 		-
 			message: "#^Method Rebing\\\\GraphQL\\\\Tests\\\\Database\\\\SelectFields\\\\ValidateDiffNodeTests\\\\UsersQuery\\:\\:resolve\\(\\) has no return type specified\\.$#"
 			count: 1
diff --git a/tests/Database/SelectFields/UnionTests/CommentType.php b/tests/Database/SelectFields/UnionTests/CommentType.php
new file mode 100644
index 00000000..b0803357
--- /dev/null
+++ b/tests/Database/SelectFields/UnionTests/CommentType.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types = 1);
+namespace Rebing\GraphQL\Tests\Database\SelectFields\UnionTests;
+
+use GraphQL\Type\Definition\Type;
+use Rebing\GraphQL\Support\Type as GraphQLType;
+use Rebing\GraphQL\Tests\Support\Models\Comment;
+
+class CommentType extends GraphQLType
+{
+    protected $attributes = [
+        'name' => 'Comment',
+        'model' => Comment::class,
+    ];
+
+    public function fields(): array
+    {
+        return [
+            'body' => [
+                'type' => Type::string(),
+            ],
+            'id' => [
+                'type' => Type::nonNull(Type::ID()),
+            ],
+            'title' => [
+                'type' => Type::nonNull(Type::string()),
+            ],
+        ];
+    }
+}
diff --git a/tests/Database/SelectFields/UnionTests/PostType.php b/tests/Database/SelectFields/UnionTests/PostType.php
new file mode 100644
index 00000000..9b3abaa5
--- /dev/null
+++ b/tests/Database/SelectFields/UnionTests/PostType.php
@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types = 1);
+namespace Rebing\GraphQL\Tests\Database\SelectFields\UnionTests;
+
+use GraphQL\Type\Definition\Type;
+use Rebing\GraphQL\Support\Facades\GraphQL;
+use Rebing\GraphQL\Support\Type as GraphQLType;
+use Rebing\GraphQL\Tests\Support\Models\Post;
+
+class PostType extends GraphQLType
+{
+    protected $attributes = [
+        'name' => 'Post',
+        'model' => Post::class,
+    ];
+
+    public function fields(): array
+    {
+        return [
+            'body' => [
+                'type' => Type::string(),
+            ],
+            'comments' => [
+                'type' => Type::nonNull(Type::listOf(Type::nonNull(GraphQL::type('Comment')))),
+                'query' => function (array $args, $query, $ctx) {
+                    $query->where('title', 'like', 'lorem');
+                },
+            ],
+            'id' => [
+                'type' => Type::nonNull(Type::ID()),
+            ],
+            'title' => [
+                'type' => Type::nonNull(Type::string()),
+            ],
+        ];
+    }
+}
diff --git a/tests/Database/SelectFields/UnionTests/SearchQuery.php b/tests/Database/SelectFields/UnionTests/SearchQuery.php
new file mode 100644
index 00000000..8f04e9cc
--- /dev/null
+++ b/tests/Database/SelectFields/UnionTests/SearchQuery.php
@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types = 1);
+namespace Rebing\GraphQL\Tests\Database\SelectFields\UnionTests;
+
+use Closure;
+use GraphQL\Type\Definition\ResolveInfo;
+use GraphQL\Type\Definition\Type;
+use Illuminate\Support\Str;
+use Rebing\GraphQL\Support\Facades\GraphQL;
+use Rebing\GraphQL\Support\Query;
+use Rebing\GraphQL\Support\SelectFields;
+use Rebing\GraphQL\Tests\Support\Models\Comment;
+use Rebing\GraphQL\Tests\Support\Models\Post;
+
+class SearchQuery extends Query
+{
+    protected $attributes = [
+        'name' => 'searchQuery',
+    ];
+
+    public function type(): Type
+    {
+        return GraphQL::type('SearchUnion');
+    }
+
+    public function args(): array
+    {
+        return [
+            'id' => [
+                'type' => Type::nonNull(Type::string()),
+            ],
+        ];
+    }
+
+    public function resolve($root, $args, $ctx, ResolveInfo $info, Closure $getSelectFields)
+    {
+        /** @var SelectFields $selectFields */
+        $selectFields = $getSelectFields();
+
+        if (Str::startsWith($args['id'], 'comment:')) {
+            return Comment::select($selectFields->getSelect())
+                ->with($selectFields->getRelations())
+                ->where('id', (int) Str::after($args['id'], 'comment:'))
+                ->first();
+        }
+
+        return Post::select($selectFields->getSelect())
+            ->with($selectFields->getRelations())
+            ->where('id', (int) $args['id'])
+            ->first();
+    }
+}
diff --git a/tests/Database/SelectFields/UnionTests/SearchUnionTest.php b/tests/Database/SelectFields/UnionTests/SearchUnionTest.php
new file mode 100644
index 00000000..b44759d4
--- /dev/null
+++ b/tests/Database/SelectFields/UnionTests/SearchUnionTest.php
@@ -0,0 +1,71 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rebing\GraphQL\Tests\Database\SelectFields\UnionTests;
+
+use Rebing\GraphQL\Tests\Support\Models\Comment;
+use Rebing\GraphQL\Tests\Support\Models\Post;
+use Rebing\GraphQL\Tests\TestCaseDatabase;
+
+class SearchUnionTest extends TestCaseDatabase
+{
+    protected function getEnvironmentSetUp($app): void
+    {
+        parent::getEnvironmentSetUp($app);
+
+        $app['config']->set('graphql.schemas.default', [
+            'query' => [
+                SearchQuery::class,
+            ],
+        ]);
+
+        $app['config']->set('graphql.types', [
+            CommentType::class,
+            PostType::class,
+            SearchUnionType::class,
+        ]);
+    }
+
+    public function testCustomQueryIsExecutedUsingUnionTypeOnQuery(): void
+    {
+        /** @var Post $post */
+        $post = factory(Post::class)->create();
+        /** @var Comment $comment1 */
+        $comment1 = factory(Comment::class)->create(['post_id' => $post->id, 'title' => 'lorem']);
+        /** @var Comment $comment2 */
+        $comment2 = factory(Comment::class)->create(['post_id' => $post->id, 'title' => 'ipsum']);
+
+        $query = <<<'GRAQPHQL'
+query ($id: String!) {
+  searchQuery(id: $id) {
+    ... on Post {
+        id
+        comments {
+            id
+        }
+    }
+    ... on Comment {
+        id
+    }
+  }
+}
+GRAQPHQL;
+
+        $result = $this->httpGraphql($query, [
+            'variables' => ['id' => (string)$post->id],
+        ]);
+
+        $expectedResult = [
+            'data' => [
+                'searchQuery' => [
+                    'id' => (string)$post->id,
+                    'comments' => [
+                        ['id' => $comment1->id],
+                    ],
+                ],
+            ],
+        ];
+        self::assertEquals($expectedResult, $result);
+    }
+}
diff --git a/tests/Database/SelectFields/UnionTests/SearchUnionType.php b/tests/Database/SelectFields/UnionTests/SearchUnionType.php
new file mode 100644
index 00000000..bab1faa3
--- /dev/null
+++ b/tests/Database/SelectFields/UnionTests/SearchUnionType.php
@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types = 1);
+namespace Rebing\GraphQL\Tests\Database\SelectFields\UnionTests;
+
+use GraphQL\Type\Definition\Type;
+use Rebing\GraphQL\Support\Facades\GraphQL;
+use Rebing\GraphQL\Support\UnionType;
+use Rebing\GraphQL\Tests\Support\Models\Comment;
+use Rebing\GraphQL\Tests\Support\Models\Post;
+
+class SearchUnionType extends UnionType
+{
+    protected $attributes = [
+        'name' => 'SearchUnion',
+    ];
+
+    public function types(): array
+    {
+        return [
+            GraphQL::type('Post'),
+            GraphQL::type('Comment'),
+        ];
+    }
+
+    /**
+     * @param object $value
+     * @return Type|null
+     */
+    public function resolveType($value): ?Type
+    {
+        if ($value instanceof Post) {
+            return GraphQL::type('Post');
+        } elseif ($value instanceof Comment) {
+            return GraphQL::type('Comment');
+        } else {
+            return null;
+        }
+    }
+}