diff --git a/bot.py b/bot.py
index f12d05c..1bcabef 100644
--- a/bot.py
+++ b/bot.py
@@ -3,7 +3,7 @@ import os
 from settings import *
 from toxcore_enums_and_consts import *
 from ctypes import *
-from util import Singleton
+from util import Singleton, folder_size
 from file_transfers import *
 from collections import defaultdict
 
@@ -112,6 +112,7 @@ class Bot(Singleton):
             message <ToxID> <message_text> - send message to friend (masters only)\n
             message --all <message_text> - send message to all friends (masters only)\n
             stop - stop bot (masters only)\n
+            fsize <folder_size_in_MB> - set folder size in MB (masters only)\n
             Users with write access can send files to bot.
             """.encode('utf-8'))
         elif message == 'rights':  # get rights
@@ -216,7 +217,7 @@ class Bot(Singleton):
                 elif bytes_size < 1024 * 1024:
                     size = u'{} KB'.format(bytes_size / 1024)
                 else:
-                    size = u'{} MB'.format(bytes_size / 1024 * 1024)
+                    size = u'{} MB'.format(bytes_size / (1024 * 1024))
                 s = u'Size: {} ({} bytes)'.format(size, bytes_size)
                 self.send_message(friend_num, s.encode('utf-8'))
         elif message.startswith('message '):  # send message to friend (all friends)
@@ -264,6 +265,17 @@ class Bot(Singleton):
                 raise SystemExit()
             else:
                 self.send_message(friend_num, 'Not enough rights'.encode('utf-8'))
+        elif message.startswith('fsize '):
+            if id not in settings['master']:
+                self.send_message(friend_num, 'Not enough rights'.encode('utf-8'))
+            else:
+                try:
+                    size = int(message[6:])
+                    settings['size'] = max(size, 10)
+                    settings.save()
+                    self.send_message(friend_num, 'Size was set'.encode('utf-8'))
+                except:
+                    self.send_message(friend_num, 'Wrong command'.encode('utf-8'))
         else:
             self.send_message(friend_num, 'Wrong command'.encode('utf-8'))
 
@@ -307,7 +319,9 @@ class Bot(Singleton):
         """
         id = self._tox.friend_get_public_key(friend_number)
         settings = Settings.get_instance()
-        if id in settings['write']:
+        fsize = folder_size(settings['folder']) + size
+        max_folder_size = settings['size'] * 1024 * 1024
+        if id in settings['write'] and fsize <= max_folder_size:
             path = settings['folder']
             new_file_name, i = file_name, 1
             while os.path.isfile(path + '/' + new_file_name):  # file with same name already exists
diff --git a/file_transfers.py b/file_transfers.py
index 32aebcc..fcb59b6 100644
--- a/file_transfers.py
+++ b/file_transfers.py
@@ -1,5 +1,5 @@
 from toxcore_enums_and_consts import TOX_FILE_KIND, TOX_FILE_CONTROL
-from os.path import basename, getsize
+from os.path import basename, getsize, remove
 from os import remove
 from time import time
 from tox import Tox
@@ -25,7 +25,7 @@ class FileTransfer(object):
         self.state = TOX_FILE_TRANSFER_STATE['RUNNING']
         self._file_number = file_number
         self._creation_time = time()
-        self._size = float(size)
+        self._size = size
         self._done = 0
 
     def set_tox(self, tox):
@@ -123,3 +123,6 @@ class ReceiveTransfer(FileTransfer):
             if position + l > self._file_size:
                 self._file_size = position + l
             self._done += l
+            if self._done > self._size:
+                self.cancel()
+                remove(self._path)
diff --git a/settings.json b/settings.json
index 110e102..626efa6 100644
--- a/settings.json
+++ b/settings.json
@@ -1 +1 @@
-{"write": ["56A1ADE4B65B86BCD51CC73E2CD4E542179F47959FE3E0E21B4B0ACDADE51855"], "auto_rights": "r", "master": [], "read": ["56A1ADE4B65B86BCD51CC73E2CD4E542179F47959FE3E0E21B4B0ACDADE51855"], "folder": "/home/tox_user/tox/shared", "delete": ["56A1ADE4B65B86BCD51CC73E2CD4E542179F47959FE3E0E21B4B0ACDADE51855"]}
\ No newline at end of file
+{"write": ["56A1ADE4B65B86BCD51CC73E2CD4E542179F47959FE3E0E21B4B0ACDADE51855"], "auto_rights": "r", "master": [], "read": ["56A1ADE4B65B86BCD51CC73E2CD4E542179F47959FE3E0E21B4B0ACDADE51855"], "folder": "/home/tox_user/tox/shared", "size": 500, "delete": ["56A1ADE4B65B86BCD51CC73E2CD4E542179F47959FE3E0E21B4B0ACDADE51855"]}
diff --git a/settings.py b/settings.py
index bd5dff5..d50cee3 100644
--- a/settings.py
+++ b/settings.py
@@ -31,7 +31,8 @@ class Settings(Singleton, dict):
             'delete': [],
             'master': [],
             'folder': curr_directory(),
-            'auto_rights': 'r'
+            'auto_rights': 'r',
+            'size': 500
         }
 
     def save(self):
diff --git a/util.py b/util.py
index 7e9aae4..8104598 100644
--- a/util.py
+++ b/util.py
@@ -10,6 +10,15 @@ def curr_directory():
     return os.path.dirname(os.path.realpath(__file__))
 
 
+def folder_size(path):
+    size = 0
+    for f in os.listdir(path):
+        f = unicode(f)
+        if os.path.isfile(os.path.join(path, f)):
+            size += os.path.getsize(os.path.join(path, f))
+    return size
+
+
 class Singleton(object):
 
     def __new__(cls, *args, **kwargs):