diff --git a/integrations/symfony-full-configuration.rst b/integrations/symfony-full-configuration.rst
index dcf90ef..76a042b 100644
--- a/integrations/symfony-full-configuration.rst
+++ b/integrations/symfony-full-configuration.rst
@@ -123,3 +123,7 @@ This page shows an example of all configuration values provided by the bundle.
                     - header_remove:
                         # List of header names to remove
                         headers: ["X-FOO"]
+                    # Sets query parameters to default value if they are not present in the request.
+                    - query_defaults:
+                        parameters:
+                            locale: en
diff --git a/plugins/index.rst b/plugins/index.rst
index 6874ceb..3788afa 100644
--- a/plugins/index.rst
+++ b/plugins/index.rst
@@ -20,6 +20,7 @@ request or you can even start a completely new request. This gives you full cont
    headers
    history
    logger
+   query
    redirect
    request-uri-manipulations
    retry
diff --git a/plugins/query.rst b/plugins/query.rst
new file mode 100644
index 0000000..5a3bc48
--- /dev/null
+++ b/plugins/query.rst
@@ -0,0 +1,24 @@
+Query plugin
+============
+
+Default Query parameters
+------------------------
+
+The plugin ``QueryDefaultsPlugin`` allows you to define default values for
+query parameters. If a query parameter is not set, it will be added. However, if the query parameter
+is already present, the request is left unchanged. Names and values must not be URL encoded as this
+plugin will encode them::
+
+    use Http\Discovery\HttpClientDiscovery;
+    use Http\Client\Common\PluginClient;
+    use Http\Client\Common\Plugin\HeaderDefaultsPlugin;
+
+    $queryDefaultsPlugin = new QueryDefaultsPlugin([
+        'locale' => 'en'
+    ]);
+
+    $pluginClient = new PluginClient(
+        HttpClientDiscovery::find(),
+        [$queryDefaultsPlugin]
+    );
+