diff --git a/CHANGELOG.md b/CHANGELOG.md
index e4c8e92c6..9a96f36d5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,8 @@
 ## [UNRELEASED] neptune-client 0.16.4
 
+## Fixes
+- fetch_extension added to Handler ([#923](https://github.com/neptune-ai/neptune-client/pull/923))
+
 ## Changes
 - Rename and copy update for UnsupportedClientVersion and DeprecatedClientLibraryVersion ([#917](https://github.com/neptune-ai/neptune-client/pull/917))
 
diff --git a/e2e_tests/standard/test_files.py b/e2e_tests/standard/test_files.py
index 959c7638d..2aa276348 100644
--- a/e2e_tests/standard/test_files.py
+++ b/e2e_tests/standard/test_files.py
@@ -50,7 +50,8 @@ def test_using_new_api(self, container: MetadataContainer):
     )
     def test_single_file(self, container: MetadataContainer, file_size: int):
         key = self.gen_key()
-        filename = fake.file_name()
+        extension = fake.file_extension()
+        filename = fake.file_name(extension=extension)
         downloaded_filename = fake.file_name()
 
         with tmp_context():
@@ -62,6 +63,7 @@ def test_single_file(self, container: MetadataContainer, file_size: int):
             container.sync()
             container[key].download(downloaded_filename)
 
+            assert container[key].fetch_extension() == extension
             assert os.path.getsize(downloaded_filename) == file_size
             with open(downloaded_filename, "rb") as file:
                 content = file.read()
diff --git a/neptune/new/attributes/atoms/file.py b/neptune/new/attributes/atoms/file.py
index beb110846..ad3d3809b 100644
--- a/neptune/new/attributes/atoms/file.py
+++ b/neptune/new/attributes/atoms/file.py
@@ -53,7 +53,7 @@ def download(self, destination: Optional[str] = None) -> None:
             self._container_id, self._container_type, self._path, destination
         )
 
-    def fetch_extension(self):
+    def fetch_extension(self) -> str:
         # pylint: disable=protected-access
         val = self._backend.get_file_attribute(self._container_id, self._container_type, self._path)
         return val.ext
diff --git a/neptune/new/handler.py b/neptune/new/handler.py
index a5eb55141..7ae8e42fe 100644
--- a/neptune/new/handler.py
+++ b/neptune/new/handler.py
@@ -479,6 +479,14 @@ def fetch_hash(self) -> str:
         """
         return self._pass_call_to_attr(function_name="fetch_hash")
 
+    def fetch_extension(self) -> str:
+        """Fetches the extension of a file.
+
+        You may also want to check `fetch_extension docs page`_.
+           https://docs.neptune.ai/api-reference/field-types#.fetch_extension
+        """
+        return self._pass_call_to_attr(function_name="fetch_extension")
+
     def fetch_files_list(self) -> List[ArtifactFileData]:
         """Fetches the list of files in an artifact and their metadata.