diff --git a/tests/Bot/Tests/DialogsTest.php b/tests/Bot/Tests/DialogsTest.php
index e8e5312..08ee4d3 100644
--- a/tests/Bot/Tests/DialogsTest.php
+++ b/tests/Bot/Tests/DialogsTest.php
@@ -72,6 +72,42 @@ class DialogsTest extends TestCase
         self::assertTrue($response->getResponsible() instanceof Responsible);
     }
 
+    /**
+     * @group("dialogs")
+     * @throws \Exception
+     */
+    public function testDialogUnassignError()
+    {
+        $this->expectException(\RuntimeException::class);
+        $client = self::getApiClient(
+            null,
+            null,
+            false,
+            $this->getErrorsResponse(400, "incorrect dialog_id")
+        );
+
+        $client->dialogUnassign(-1);
+    }
+
+    /**
+     * @group("dialogs")
+     * @throws \Exception
+     */
+    public function testDialogUnassign()
+    {
+        $client = self::getApiClient(
+            null,
+            null,
+            false,
+            $this->getJsonResponse('dialogUnassigned')
+        );
+
+        $response = $client->dialogUnassign(60);
+
+        self::assertTrue($response->isSuccessful());
+        self::assertTrue($response->getPreviousResponsible() instanceof Responsible);
+    }
+
     /**
      * @group("dialogs")
      * @throws \Exception
diff --git a/tests/Resources/dialogUnassigned.json b/tests/Resources/dialogUnassigned.json
new file mode 100644
index 0000000..08d2c42
--- /dev/null
+++ b/tests/Resources/dialogUnassigned.json
@@ -0,0 +1 @@
+{"previous_responsible":{"type":"user","id":12,"assigned_at":"2019-06-11T12:49:34Z"}}
\ No newline at end of file