diff --git a/hapic/data.py b/hapic/data.py
index cd984b9..588bd9e 100644
--- a/hapic/data.py
+++ b/hapic/data.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 import typing
 import urllib.parse
+from datetime import datetime
 
 
 class HapicData(object):
@@ -20,6 +21,8 @@ def __init__(
         file_object: typing.Any = None,
         mimetype: typing.Any = None,
         filename: str = None,
+        content_length: int = None,
+        last_modified: datetime = None,
         as_attachment: bool = False,
     ):
         self.file_path = file_path
@@ -27,6 +30,8 @@ def __init__(
         self.filename = filename
         self.mimetype = mimetype
         self.as_attachment = as_attachment
+        self.content_length = content_length
+        self.last_modified = last_modified
 
     def get_content_disposition_header_value(self) -> str:
         disposition = "inline"
diff --git a/hapic/ext/pyramid/context.py b/hapic/ext/pyramid/context.py
index 38b362f..e6fdf4c 100644
--- a/hapic/ext/pyramid/context.py
+++ b/hapic/ext/pyramid/context.py
@@ -111,6 +111,11 @@ def get_file_response(self, file_response: HapicFile, http_code: int):
             response.content_type = file_response.mimetype
             response.app_iter = FileIter(file_response.file_object)
 
+        if file_response.content_length:
+            response.content_length = file_response.content_length
+        if file_response.last_modified:
+            response.last_modified = file_response.last_modified
+
         response.status_code = http_code
         response.content_disposition = (
             file_response.get_content_disposition_header_value()
diff --git a/hapic/processor/main.py b/hapic/processor/main.py
index f055359..5aab8ad 100644
--- a/hapic/processor/main.py
+++ b/hapic/processor/main.py
@@ -1,6 +1,7 @@
 import abc
 import os
 import typing
+from datetime import datetime
 
 from apispec import BasePlugin
 from multidict.__init__ import MultiDict
@@ -213,6 +214,12 @@ def _get_ouput_file_validation_error_message(
             error_message = "File path is not correct, file do not exist"
         elif data.file_object and not data.mimetype:
             error_message = "File object should have explicit mimetype"
+        elif data.content_length and not isinstance(data.content_length, int):
+            error_message = "Content length should be integer"
+        elif data.content_length and data.content_length < 0:
+            error_message = "Content length should positive or null integer"
+        elif data.last_modified and not isinstance(data.last_modified, datetime):
+            error_message = "Last-modified value should be datetime type"
         return error_message
 
     # NOTE BS 2018-12-20: the decorators order is not semantically right,
diff --git a/tests/unit/test_processor.py b/tests/unit/test_processor.py
index 35926d5..0cd9795 100644
--- a/tests/unit/test_processor.py
+++ b/tests/unit/test_processor.py
@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from datetime import datetime
 from io import BytesIO
 import os
 
@@ -26,7 +27,7 @@ def test_unit_file_output_processor_ok__process_success_filepath(self):
         data = processor.dump_output_file(tested_data)
         assert data == tested_data
 
-    def test_unit_file_output_processor_ok__process_success_fileobject(self):
+    def test_unit_file_output_processor_ok__process_success_fileobject_as_stream(self):
         processor = MarshmallowProcessor()
         file = BytesIO()
         image = Image.new("RGBA", size=(1000, 1000), color=(0, 0, 0))
@@ -37,6 +38,50 @@ def test_unit_file_output_processor_ok__process_success_fileobject(self):
         data = processor.dump_output_file(tested_data)
         assert data == tested_data
 
+    def test_unit_file_output_processor_ok__process_success_fileobject_as_sized_file(self):
+        processor = MarshmallowProcessor()
+        file = BytesIO()
+        image = Image.new("RGBA", size=(1000, 1000), color=(0, 0, 0))
+        image.save(file, "png")
+        file.name = "test_image.png"
+        file.seek(0)
+        tested_data = HapicFile(file_object=file, mimetype="image/png", content_length=file.getbuffer().nbytes, last_modified=datetime.utcnow())
+        data = processor.dump_output_file(tested_data)
+        assert data == tested_data
+
+    def test_unit_file_output_processor__err__bad_last_modified_type(self):
+        processor = MarshmallowProcessor()
+        file = BytesIO()
+        image = Image.new("RGBA", size=(1000, 1000), color=(0, 0, 0))
+        image.save(file, "png")
+        file.name = "test_image.png"
+        file.seek(0)
+        tested_data = HapicFile(file_object=file, mimetype="image/png", last_modified='uncorrect_type')
+        with pytest.raises(ValidationException):
+            data = processor.dump_output_file(tested_data)
+
+    def test_unit_file_output_processor__err__bad_content_length_type(self):
+        processor = MarshmallowProcessor()
+        file = BytesIO()
+        image = Image.new("RGBA", size=(1000, 1000), color=(0, 0, 0))
+        image.save(file, "png")
+        file.name = "test_image.png"
+        file.seek(0)
+        tested_data = HapicFile(file_object=file, mimetype="image/png", content_length='uncorrect_type')
+        with pytest.raises(ValidationException):
+            data = processor.dump_output_file(tested_data)
+
+    def test_unit_file_output_processor__err__negative_content_length(self):
+        processor = MarshmallowProcessor()
+        file = BytesIO()
+        image = Image.new("RGBA", size=(1000, 1000), color=(0, 0, 0))
+        image.save(file, "png")
+        file.name = "test_image.png"
+        file.seek(0)
+        tested_data = HapicFile(file_object=file, mimetype="image/png", content_length=-1)
+        with pytest.raises(ValidationException):
+            data = processor.dump_output_file(tested_data)
+
     def test_unit_file_output_processor_err__wrong_type(self):
         processor = MarshmallowProcessor()
         file = BytesIO()