diff --git a/pybotx/models/message/markup.py b/pybotx/models/message/markup.py
index 832a622d..f3ab683c 100644
--- a/pybotx/models/message/markup.py
+++ b/pybotx/models/message/markup.py
@@ -19,7 +19,7 @@ class Button:
     data: Dict[str, Any] = field(default_factory=dict)
     text_color: Missing[str] = Undefined
     background_color: Missing[str] = Undefined
-    align: Missing[ButtonTextAlign] = Undefined
+    align: ButtonTextAlign = ButtonTextAlign.CENTER
 
     silent: bool = True  # BotX has `False` as default, so Missing type can't be used
     width_ratio: Missing[int] = Undefined
@@ -73,7 +73,7 @@ def add_button(
         data: Optional[Dict[str, Any]] = None,
         text_color: Missing[str] = Undefined,
         background_color: Missing[str] = Undefined,
-        align: Missing[ButtonTextAlign] = Undefined,
+        align: ButtonTextAlign = ButtonTextAlign.CENTER,
         silent: bool = True,
         width_ratio: Missing[int] = Undefined,
         alert: Missing[str] = Undefined,
diff --git a/pyproject.toml b/pyproject.toml
index ddc5ef8a..cf38dcc7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "pybotx"
-version = "0.55.6"
+version = "0.55.7"
 description = "A python library for interacting with eXpress BotX API"
 authors = [
     "Sidnev Nikolay <nsidnev@ccsteam.ru>",
diff --git a/tests/client/events_api/test_edit_event.py b/tests/client/events_api/test_edit_event.py
index e8063c84..947d9c1f 100644
--- a/tests/client/events_api/test_edit_event.py
+++ b/tests/client/events_api/test_edit_event.py
@@ -88,7 +88,7 @@ async def test__edit_message__maximum_edit_succeed(
                             "command": "/bubble-button",
                             "data": {},
                             "label": "Bubble button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -98,7 +98,7 @@ async def test__edit_message__maximum_edit_succeed(
                             "command": "/keyboard-button",
                             "data": {},
                             "label": "Keyboard button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -234,7 +234,7 @@ async def test__edit__succeed(
                             "command": "/bubble-button",
                             "data": {},
                             "label": "Bubble button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -244,7 +244,7 @@ async def test__edit__succeed(
                             "command": "/keyboard-button",
                             "data": {},
                             "label": "Keyboard button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
diff --git a/tests/client/events_api/test_reply_event.py b/tests/client/events_api/test_reply_event.py
index b60e0f18..b0565525 100644
--- a/tests/client/events_api/test_reply_event.py
+++ b/tests/client/events_api/test_reply_event.py
@@ -99,7 +99,7 @@ async def test__reply_message__maximum_filled_reply_succeed(
                             "command": "/bubble-button",
                             "label": "Bubble button",
                             "data": {},
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -109,7 +109,7 @@ async def test__reply_message__maximum_filled_reply_succeed(
                             "command": "/keyboard-button",
                             "label": "Keyboard button",
                             "data": {},
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -209,7 +209,7 @@ async def test__reply__succeed(
                             "command": "/bubble-button",
                             "label": "Bubble button",
                             "data": {},
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -219,7 +219,7 @@ async def test__reply__succeed(
                             "command": "/keyboard-button",
                             "label": "Keyboard button",
                             "data": {},
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
diff --git a/tests/client/notifications_api/test_direct_notification.py b/tests/client/notifications_api/test_direct_notification.py
index 9dad8e30..02f393b6 100644
--- a/tests/client/notifications_api/test_direct_notification.py
+++ b/tests/client/notifications_api/test_direct_notification.py
@@ -61,7 +61,7 @@ async def test__send__succeed(
                             "command": "/bubble-button",
                             "data": {},
                             "label": "Bubble button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -71,7 +71,7 @@ async def test__send__succeed(
                             "command": "/keyboard-button",
                             "data": {},
                             "label": "Keyboard button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -205,7 +205,7 @@ async def test__answer_message__succeed(
                             "command": "/bubble-button",
                             "data": {},
                             "label": "Bubble button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -215,7 +215,7 @@ async def test__answer_message__succeed(
                             "command": "/keyboard-button",
                             "data": {},
                             "label": "Keyboard button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -650,6 +650,7 @@ async def test__send_message__maximum_filled_succeed(
                                 "alert_text": "Alert text 1",
                                 "show_alert": True,
                                 "handler": "client",
+                                "align": "center",
                             },
                         },
                     ],
@@ -665,6 +666,7 @@ async def test__send_message__maximum_filled_succeed(
                                 "h_size": 2,
                                 "alert_text": "Alert text 2",
                                 "show_alert": True,
+                                "align": "center",
                             },
                         },
                     ],
diff --git a/tests/client/notifications_api/test_markup.py b/tests/client/notifications_api/test_markup.py
index 13e51643..3b80e130 100644
--- a/tests/client/notifications_api/test_markup.py
+++ b/tests/client/notifications_api/test_markup.py
@@ -45,7 +45,7 @@ async def test__markup__defaults_filled(
                             "command": "/bubble-button",
                             "data": {},
                             "label": "Bubble button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -55,7 +55,7 @@ async def test__markup__defaults_filled(
                             "command": "/keyboard-button",
                             "data": {},
                             "label": "Keyboard button",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],
@@ -133,13 +133,13 @@ async def test__markup__correctly_built(
                             "command": "/bubble-button-1",
                             "data": {},
                             "label": "Bubble button 1",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                         {
                             "command": "/bubble-button-2",
                             "data": {},
                             "label": "Bubble button 2",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                     [
@@ -147,7 +147,7 @@ async def test__markup__correctly_built(
                             "command": "/bubble-button-3",
                             "data": {},
                             "label": "Bubble button 3",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                     [
@@ -155,13 +155,13 @@ async def test__markup__correctly_built(
                             "command": "/bubble-button-4",
                             "data": {},
                             "label": "Bubble button 4",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                         {
                             "command": "/bubble-button-5",
                             "data": {},
                             "label": "Bubble button 5",
-                            "opts": {"silent": True},
+                            "opts": {"silent": True, "align": "center"},
                         },
                     ],
                 ],