diff --git a/elasticsearch/client/utils.py b/elasticsearch/client/utils.py
index 2327d823..5500128a 100644
--- a/elasticsearch/client/utils.py
+++ b/elasticsearch/client/utils.py
@@ -57,7 +57,9 @@ def query_params(*es_query_params):
     def _wrapper(func):
         @wraps(func)
         def _wrapped(*args, **kwargs):
-            params = kwargs.pop('params', {})
+            params = {}
+            if 'params' in kwargs:
+                params = kwargs.pop('params').copy()
             for p in es_query_params + GLOBAL_PARAMS:
                 if p in kwargs:
                     v = kwargs.pop(p)
diff --git a/test_elasticsearch/test_client/__init__.py b/test_elasticsearch/test_client/__init__.py
index dacf8e42..4bf2978c 100644
--- a/test_elasticsearch/test_client/__init__.py
+++ b/test_elasticsearch/test_client/__init__.py
@@ -54,6 +54,21 @@ class TestClient(ElasticsearchTestCase):
         calls = self.assert_url_called('HEAD', '/')
         self.assertEquals([({'request_timeout': .1}, None)], calls)
 
+    def test_params_is_copied_when(self):
+        rt = object()
+        params = dict(request_timeout=rt)
+        self.client.ping(params=params)
+        self.client.ping(params=params)
+        calls = self.assert_url_called('HEAD', '/', 2)
+        self.assertEquals(
+            [
+                ({'request_timeout': rt}, None),
+                ({'request_timeout': rt}, None)
+            ],
+            calls
+        )
+        self.assertFalse(calls[0][0] is calls[1][0])
+
     def test_from_in_search(self):
         self.client.search(index='i', doc_type='t', from_=10)
         calls = self.assert_url_called('GET', '/i/t/_search')