diff --git a/src/JsonSchema/Constraints/CollectionConstraint.php b/src/JsonSchema/Constraints/CollectionConstraint.php
index b1dcf35c..b43baced 100644
--- a/src/JsonSchema/Constraints/CollectionConstraint.php
+++ b/src/JsonSchema/Constraints/CollectionConstraint.php
@@ -33,7 +33,7 @@ public function check($value, $schema = null, $path = null, $i = null)
         }
 
         // Verify uniqueItems
-        if (isset($schema->uniqueItems)) {
+        if (isset($schema->uniqueItems) && $schema->uniqueItems) {
             $unique = $value;
             if (is_array($value) && count($value)) {
                 $unique = array_map(function($e) { return var_export($e, true); }, $value);
diff --git a/tests/JsonSchema/Tests/Constraints/UniqueItemsTest.php b/tests/JsonSchema/Tests/Constraints/UniqueItemsTest.php
index 3006bb43..4abac569 100644
--- a/tests/JsonSchema/Tests/Constraints/UniqueItemsTest.php
+++ b/tests/JsonSchema/Tests/Constraints/UniqueItemsTest.php
@@ -110,6 +110,49 @@ public function getValidTests()
                     "type": "array",
                     "uniqueItems": true
                 }'
+            ),
+            // below equals the invalid tests, but with uniqueItems set to false
+            array(
+                '[1,2,2]',
+                '{
+                  "type":"array",
+                  "uniqueItems": false
+                }'
+            ),
+            array(
+                '[{"a":"b"},{"a":"c"},{"a":"b"}]',
+                '{
+                  "type":"array",
+                  "uniqueItems": false
+                }'
+            ),
+            array(
+                '[{"foo": {"bar" : {"baz" : true}}}, {"foo": {"bar" : {"baz" : true}}}]',
+                '{
+                    "type": "array",
+                    "uniqueItems": false
+                }'
+            ),
+            array(
+                '[1.0, 1.00, 1]',
+                '{
+                    "type": "array",
+                    "uniqueItems": false
+                }'
+            ),
+            array(
+                '[["foo"], ["foo"]]',
+                '{
+                    "type": "array",
+                    "uniqueItems": false
+                }'
+            ),
+            array(
+                '[{}, [1], true, null, {}, 1]',
+                '{
+                    "type": "array",
+                    "uniqueItems": false
+                }'
             )
         );
     }