diff --git a/src/Validator/DocumentValidator.php b/src/Validator/DocumentValidator.php
index f00dfb9..b70cdc8 100644
--- a/src/Validator/DocumentValidator.php
+++ b/src/Validator/DocumentValidator.php
@@ -118,8 +118,11 @@ class DocumentValidator
 
     public static function validate(Schema $schema, DocumentNode $ast, array $rules = null, TypeInfo $typeInfo = null)
     {
+        if (null === $rules) {
+            $rules = static::allRules();
+        }
         $typeInfo = $typeInfo ?: new TypeInfo($schema);
-        $errors = static::visitUsingRules($schema, $typeInfo, $ast, $rules ?: static::allRules());
+        $errors = static::visitUsingRules($schema, $typeInfo, $ast, $rules);
         return $errors;
     }
 
diff --git a/tests/Validator/ValidationTest.php b/tests/Validator/ValidationTest.php
index 018ee33..55f1059 100644
--- a/tests/Validator/ValidationTest.php
+++ b/tests/Validator/ValidationTest.php
@@ -23,4 +23,16 @@ class ValidationTest extends TestCase
           }
         ');
     }
+
+    public function testPassesValidationWithEmptyRules()
+    {
+        $query = '{invalid}';
+
+        $expectedError = [
+            'message' => 'Cannot query field "invalid" on type "QueryRoot".',
+            'locations' => [ ['line' => 1, 'column' => 2] ]
+        ];
+        $this->expectFailsCompleteValidation($query, [$expectedError]);
+        $this->expectValid($this->getDefaultSchema(), [], $query);
+    }
 }