diff --git a/CHANGELOG.md b/CHANGELOG.md
index fd0cd2c..c8fc1a6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,11 @@
 Changelog
 =========
 
+v0.3.5 (2023-10-02)
+-------------------
+* Delete `Serializable` class
+* Add `__hash__` method to `BBox`
+
 v0.3.4 (2023-09-28)
 -------------------
 * Add `Serializable` class
diff --git a/VERSION b/VERSION
index 448a0fa..09e9157 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.3.4
\ No newline at end of file
+0.3.5
\ No newline at end of file
diff --git a/dedocutils/data_structures/bbox.py b/dedocutils/data_structures/bbox.py
index 310de53..78dcf8b 100644
--- a/dedocutils/data_structures/bbox.py
+++ b/dedocutils/data_structures/bbox.py
@@ -5,11 +5,9 @@
 
 import numpy as np
 
-from dedocutils.data_structures.serializable import Serializable
-
 
 @dataclass
-class BBox(Serializable):
+class BBox:
     """
     Bounding box around some page object, the coordinate system starts from top left corner.
     """
@@ -138,3 +136,6 @@ def to_relative_dict(self, page_width: int, page_height: int) -> dict:
     @staticmethod
     def from_dict(some_dict: Dict[str, int]) -> "BBox":
         return BBox(**some_dict)
+
+    def __hash__(self) -> int:
+        return hash((self.x_top_left, self.y_top_left, self.width, self.height))
diff --git a/dedocutils/data_structures/serializable.py b/dedocutils/data_structures/serializable.py
deleted file mode 100644
index 9de5d23..0000000
--- a/dedocutils/data_structures/serializable.py
+++ /dev/null
@@ -1,16 +0,0 @@
-from abc import ABC, abstractmethod
-
-
-class Serializable(ABC):
-    """
-    Base class for the serializable objects which we need convert to dict.
-    """
-    @abstractmethod
-    def to_dict(self) -> dict:
-        """
-        Convert class data into dictionary representation.
-        Dictionary key should be string and dictionary value should be json serializable.
-
-        :return: dict with all class data.
-        """
-        pass