diff --git a/src/JsonSchema/Constraints/Constraint.php b/src/JsonSchema/Constraints/Constraint.php
index a6f57aef..7975d663 100644
--- a/src/JsonSchema/Constraints/Constraint.php
+++ b/src/JsonSchema/Constraints/Constraint.php
@@ -100,10 +100,10 @@ protected function checkArray($value, $schema = null, $path = null, $i = null)
      * @param mixed $path
      * @param mixed $i
      */
-    protected function checkObject($value, $schema = null, $path = null, $i = null)
+    protected function checkObject($value, $schema = null, $path = null, $i = null, $patternProperties = null)
     {
         $validator = new Object($this->checkMode);
-        $validator->check($value, $schema, $path, $i);
+        $validator->check($value, $schema, $path, $i, $patternProperties);
 
         $this->addErrors($validator->getErrors());
     }
@@ -195,4 +195,4 @@ public function isValid()
     {
         return !$this->getErrors();
     }
-}
\ No newline at end of file
+}
diff --git a/src/JsonSchema/Constraints/Object.php b/src/JsonSchema/Constraints/Object.php
index 9e7ff043..2f77bcd3 100644
--- a/src/JsonSchema/Constraints/Object.php
+++ b/src/JsonSchema/Constraints/Object.php
@@ -13,15 +13,33 @@ class Object extends Constraint
     /**
      * {inheritDoc}
      */
-    function check($element, $definition = null, $path = null, $additionalProp = null)
+    function check($element, $definition = null, $path = null, $additionalProp = null, $patternProperties = null)
     {
-        // validate the definition properties
-        $this->validateDefinition($element, $definition, $path);
+        if ($patternProperties) {
+            $this->validatePatternProperties($element, $path, $additionalProp, $patternProperties);
+        }
+
+        if ($definition) {
+            // validate the definition properties
+            $this->validateDefinition($element, $definition, $path);
+        }
 
         // additional the element properties
         $this->validateElement($element, $definition, $path, $additionalProp);
     }
 
+    public function validatePatternProperties($element, $path, $additionalProp, $patternProperties)
+    {
+        foreach ($patternProperties as $pregex => $schema) {
+
+            foreach ($element as $i => $value) {
+                if (preg_match('/'.$pregex.'/', $i)) {
+                    $this->checkUndefined($value, $schema ? : new \stdClass(), $path, $i);
+                }
+            }
+        }
+    }
+
     /**
      * validates the element properties
      *
@@ -97,4 +115,4 @@ protected function getProperty($element, $property, $fallback = null)
 
         return $fallback;
     }
-}
\ No newline at end of file
+}
diff --git a/src/JsonSchema/Constraints/Schema.php b/src/JsonSchema/Constraints/Schema.php
index 0f52b383..da459754 100644
--- a/src/JsonSchema/Constraints/Schema.php
+++ b/src/JsonSchema/Constraints/Schema.php
@@ -25,4 +25,4 @@ public function check($element, $schema = null, $path = null, $i = null)
             throw new \InvalidArgumentException('no schema found to verify against');
         }
     }
-}
\ No newline at end of file
+}
diff --git a/src/JsonSchema/Constraints/Undefined.php b/src/JsonSchema/Constraints/Undefined.php
index 524bf830..70f1980f 100644
--- a/src/JsonSchema/Constraints/Undefined.php
+++ b/src/JsonSchema/Constraints/Undefined.php
@@ -46,8 +46,14 @@ public function validateTypes($value, $schema = null, $path = null, $i = null)
         }
 
         // check object
-        if (is_object($value) && isset($schema->properties)) {
-            $this->checkObject($value, $schema->properties, $path, isset($schema->additionalProperties) ? $schema->additionalProperties : null);
+        if (is_object($value) && (isset($schema->properties) || isset($schema->patternProperties))) {
+            $this->checkObject(
+                $value, 
+                isset($schema->properties) ? $schema->properties : null, 
+                $path, 
+                isset($schema->additionalProperties) ? $schema->additionalProperties : null,
+                isset($schema->patternProperties) ? $schema->patternProperties : null
+            );
         }
 
         // check string
@@ -104,4 +110,4 @@ protected function validateCommonProperties($value, $schema = null, $path = null
             }
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/JsonSchema/Tests/PatternPropertiesTest.php b/tests/JsonSchema/Tests/PatternPropertiesTest.php
new file mode 100644
index 00000000..8bb344a2
--- /dev/null
+++ b/tests/JsonSchema/Tests/PatternPropertiesTest.php
@@ -0,0 +1,72 @@
+<?php
+
+namespace JsonSchema\Tests;
+
+class PatternPropertiesTest extends BaseTestCase
+{
+    public function getInvalidTests()
+    {
+        return array(
+            // matches pattern but invalid schema for object
+            array(
+                json_encode(array(
+                    'someobject' => array(
+                        'foobar' => 'foo',
+                        'barfoo' => 'bar',
+                    )
+                )),
+                json_encode(array(
+                    'type' => 'object',
+                    'patternProperties' => array(
+                        '^someobject$' => array(
+                            'type' => 'object',
+                            'additionalProperties' => false,
+                            'properties' => array(
+                                'barfoo' => array(
+                                    'type' => 'string',
+                                ),
+                            )
+                        )
+                    )
+                ))
+            ),
+        );
+    }
+
+    public function getValidTests()
+    {
+        return array(
+            array(
+                // validates pattern schema
+                json_encode(array(
+                    'someobject' => array(
+                        'foobar' => 'foo',
+                        'barfoo' => 'bar',
+                    ),
+                    'someotherobject' => array(
+                        'foobar' => 1234,
+                    )
+                )),
+                json_encode(array(
+                    'type' => 'object',
+                    'patternProperties' => array(
+                        '^someobject$' => array(
+                            'type' => 'object',
+                            'properties' => array(
+                                'foobar' => array('type' => 'string'),
+                                'barfoo' => array('type' => 'string'),
+                            ),
+                        ),
+                        '^someotherobject$' => array(
+                            'type' => 'object',
+                            'properties' => array(
+                                'foobar' => array('type' => 'number'),
+                            ),
+                        ),
+                    )
+                ))
+            ),
+        );
+    }
+}
+