diff --git a/src/HttpMethodsClient.php b/src/HttpMethodsClient.php
index 9b6bec2..8e0cb0c 100644
--- a/src/HttpMethodsClient.php
+++ b/src/HttpMethodsClient.php
@@ -11,6 +11,14 @@
  *
  * Use this interface when you do not have PSR-7 RequestInterface instances available.
  *
+ * Implementations should be configured in their constructor. For runtime behaviour changes, there
+ * is an $options parameter. It SHOULD be validated by the client and an exception thrown if
+ * unknown options are passed.
+ * Option that must be accepted by every client implementation (though it is free to ignore them
+ * if the underlying implementation does not support the option):
+ *
+ *   - timeout (int): the timeout for the HTTP request in seconds. 0 means to use the default.
+ *
  * @author Márk Sági-Kazár mark.sagikazar@gmail.com>
  */
 interface HttpMethodsClient
diff --git a/src/HttpPsrClient.php b/src/HttpPsrClient.php
index 5215fa2..dadece4 100644
--- a/src/HttpPsrClient.php
+++ b/src/HttpPsrClient.php
@@ -9,6 +9,14 @@
 /**
  * Sends one or more PSR-7 Request
  *
+ * Implementations should be configured in their constructor. For runtime behaviour changes, there
+ * is an $options parameter. It SHOULD be validated by the client and an exception thrown if
+ * unknown options are passed.
+ * Option that must be accepted by every client implementation (though it is free to ignore them
+ * if the underlying implementation does not support the option):
+ *
+ *   - timeout (int): the timeout for the HTTP request in seconds. 0 means to use the default.
+ *
  * @author GeLo <geloen.eric@gmail.com>
  */
 interface HttpPsrClient