diff --git a/README.md b/README.md
index 06e209c..60027bf 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,11 @@
 
 **Factory interfaces for PSR-7 HTTP Message.**
 
+## Deprecation notice
+
+This package and these PSR-7 factory interfaces are deprecated. We have succeeded with our goal of moving these
+interfaces to PHP-FIG. The new [PSR-17](https://packagist.org/packages/psr/http-factory) package is backwards compatible
+with this package. (Except for the new PSR-17 is PHP7 only.)
 
 ## Install
 
diff --git a/src/MessageFactory.php b/src/MessageFactory.php
index 965aaa8..cd88f7f 100644
--- a/src/MessageFactory.php
+++ b/src/MessageFactory.php
@@ -6,6 +6,8 @@
  * Factory for PSR-7 Request and Response.
  *
  * @author Márk Sági-Kazár <mark.sagikazar@gmail.com>
+ *
+ * @deprecated Please use PSR-17 instead
  */
 interface MessageFactory extends RequestFactory, ResponseFactory
 {
diff --git a/src/RequestFactory.php b/src/RequestFactory.php
index 624e82f..712f778 100644
--- a/src/RequestFactory.php
+++ b/src/RequestFactory.php
@@ -10,6 +10,8 @@
  * Factory for PSR-7 Request.
  *
  * @author Márk Sági-Kazár <mark.sagikazar@gmail.com>
+ *
+ * @deprecated Please use PSR-17 instead
  */
 interface RequestFactory
 {
diff --git a/src/ResponseFactory.php b/src/ResponseFactory.php
index 2411ed3..25c916a 100644
--- a/src/ResponseFactory.php
+++ b/src/ResponseFactory.php
@@ -11,6 +11,8 @@
  * This factory contract can be reused in Message and Server Message factories.
  *
  * @author Márk Sági-Kazár <mark.sagikazar@gmail.com>
+ *
+ * @deprecated Please use PSR-17 instead
  */
 interface ResponseFactory
 {
diff --git a/src/StreamFactory.php b/src/StreamFactory.php
index e151389..d8a7aca 100644
--- a/src/StreamFactory.php
+++ b/src/StreamFactory.php
@@ -8,6 +8,8 @@
  * Factory for PSR-7 Stream.
  *
  * @author Márk Sági-Kazár <mark.sagikazar@gmail.com>
+ *
+ * @deprecated Please use PSR-17 instead
  */
 interface StreamFactory
 {
diff --git a/src/UriFactory.php b/src/UriFactory.php
index e8d8f90..651c98b 100644
--- a/src/UriFactory.php
+++ b/src/UriFactory.php
@@ -8,6 +8,8 @@
  * Factory for PSR-7 URI.
  *
  * @author Márk Sági-Kazár <mark.sagikazar@gmail.com>
+ *
+ * @deprecated Please use PSR-17 instead
  */
 interface UriFactory
 {