diff --git a/CHANGELOG.md b/CHANGELOG.md
index 653fd30..7d25a07 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,7 +9,9 @@ This project adheres to [Semantic Versioning](http://semver.org/).
   - Usage of `Api:api` with not fully qualified class name
   - Usage of `Api::HTTP_RESPONSE_*` constants
   - Usage of response format other than `json`
-  - Passing a string as `$params` to the methods `create` and `update` of the `PullRequests`, `BranchRestrictions`, and `Repository` API
+  - Passing a string as `$params` to the methods `create` and `update` of the `PullRequests`, `BranchRestrictions`, `Pipelines`, and `Repository` API
+  - `ClientInterface`, use `Client` instead
+  - Passing a string as `$params` to the `request` method of `Client`
 
 ## 2.1.0 / 2021-07-23
 
diff --git a/lib/Bitbucket/API/Http/Client.php b/lib/Bitbucket/API/Http/Client.php
index f038c0f..2dabe3e 100644
--- a/lib/Bitbucket/API/Http/Client.php
+++ b/lib/Bitbucket/API/Http/Client.php
@@ -130,6 +130,8 @@ public function request($endpoint, $params = array(), $method = 'GET', array $he
         }
 
         if (is_string($params) && $params !== null) {
+            trigger_deprecation('private-packagist/bitbucket-api', '2.2', 'Calling Client::request() with a string as params argument is deprecated. Pass an array instead.');
+
             $body = $params;
         }
 
diff --git a/lib/Bitbucket/API/Http/ClientInterface.php b/lib/Bitbucket/API/Http/ClientInterface.php
index b5bc695..ea349c1 100644
--- a/lib/Bitbucket/API/Http/ClientInterface.php
+++ b/lib/Bitbucket/API/Http/ClientInterface.php
@@ -16,6 +16,7 @@
 
 /**
  * @author  Alexandru G.    <alex@gentle.ro>
+ * @deprecated The ClientInterface will be removed with 3.0, depend on client directly.
  */
 interface ClientInterface
 {
diff --git a/lib/Bitbucket/API/Repositories/Pipelines.php b/lib/Bitbucket/API/Repositories/Pipelines.php
index a18e0de..a2f5afd 100644
--- a/lib/Bitbucket/API/Repositories/Pipelines.php
+++ b/lib/Bitbucket/API/Repositories/Pipelines.php
@@ -47,7 +47,9 @@ public function all($account, $repo)
     public function create($account, $repo, $params = array())
     {
         // allow developer to directly specify params as json if (s)he wants.
-        if ('array' !== gettype($params)) {
+        if (!is_array($params)) {
+            trigger_deprecation('private-packagist/bitbucket-api', '2.2', 'Calling Pipelines::create() with a string as params argument is deprecated. Pass an array instead.');
+
             if (empty($params)) {
                 throw new \InvalidArgumentException('Invalid JSON provided.');
             }