diff --git a/.gitignore b/.gitignore
index 0b96173..c00be02 100644
--- a/.gitignore
+++ b/.gitignore
@@ -223,3 +223,4 @@ cython_debug/
 # Other
 /dev.py
 /*.db
+/*.db.*
diff --git a/ptvp35/__init__.py b/ptvp35/__init__.py
index 6aad4d4..cd8cc3b 100644
--- a/ptvp35/__init__.py
+++ b/ptvp35/__init__.py
@@ -3,23 +3,27 @@ import json
 import pathlib
 import pickle
 import shutil
+import traceback
 from io import StringIO
 from typing import Any, Optional, IO, Type, Hashable
 
 
 class Request:
+    def __init__(self, future: Optional[asyncio.Future]):
+        self.future = future
+
     def set_result(self, result):
-        raise NotImplementedError
+        self.future and self.future.set_result(result)
 
     def set_exception(self, exception):
-        raise NotImplementedError
+        self.future and self.future.set_exception(exception)
 
 
 class KVRequest(Request):
     def __init__(self, key: Any, value: Any, future: Optional[asyncio.Future]):
+        super().__init__(future)
         self.key = key
         self.value = value
-        self.future = future
 
     def free(self):
         return type(self)(self.key, self.value, None)
@@ -31,22 +35,9 @@ class KVRequest(Request):
     def fromline(cls, line: str) -> 'KVRequest':
         raise NotImplementedError
 
-    def set_result(self, result):
-        self.future and self.future.set_result(result)
-
-    def set_exception(self, exception):
-        self.future and self.future.set_exception(exception)
-
 
 class DumpRequest(Request):
-    def __init__(self, future: Optional[asyncio.Future]):
-        self.future = future
-
-    def set_result(self, result):
-        self.future and self.future.set_result(result)
-
-    def set_exception(self, exception):
-        self.future and self.future.set_exception(exception)
+    pass
 
 
 class UnkownRequestType(TypeError):
@@ -83,10 +74,19 @@ class KVJson(KVRequest):
         return KVJson(cls._load_key(d['key']), d['value'], None)
 
 
+class ErrorRequest(Request):
+    def __init__(self, line: str, future: Optional[asyncio.Future]):
+        super().__init__(future)
+        self.line = line
+
+    async def wait(self):
+        await self.future
+
+
 class Db:
     __mmdb: Optional[dict]
     __loop: Optional[asyncio.AbstractEventLoop]
-    __queue: Optional[asyncio.Queue]
+    __queue: Optional[asyncio.Queue[Request]]
     __file: Optional[IO[str]]
     __buffer: Optional[StringIO]
     __task: Optional[asyncio.Future]
@@ -98,14 +98,24 @@ class Db:
         self.__path = pathlib.Path(path)
         self.__path_backup = pathlib.Path(path + '.backup')
         self.__path_recover = pathlib.Path(path + '.recover')
+        self.__path_error = pathlib.Path(path + '.error')
         self.__task = None
 
+    def _queue_error(self, line: str):
+        request = ErrorRequest(line, self.__loop.create_future())
+        self.__queue.put_nowait(request)
+        self.__loop.create_task(request.wait())
+
     def io2db(self, io: IO[str], db: dict) -> int:
         size = 0
         for line in io:
-            request = self.kvrequest_type.fromline(line)
-            db[request.key] = request.value
-            size += len(line)
+            try:
+                request = self.kvrequest_type.fromline(line)
+                db[request.key] = request.value
+                size += len(line)
+            except (json.JSONDecodeError, pickle.UnpicklingError, EOFError):
+                traceback.print_exc()
+                self._queue_error(line)
         return size
 
     def db2io(self, db: dict, io: IO[str]) -> int:
@@ -166,12 +176,18 @@ class Db:
             await self._do_dump_buffer()
             await self._reload_if_oversized()
 
+    async def _save_error(self, line: str):
+        with open(self.__path_error, 'a') as file:
+            await self.__loop.run_in_executor(None, file.write, line.strip() + '\n')
+
     async def _handle_request(self, request: Request):
         if isinstance(request, self.kvrequest_type):
             await self._write(request.line(), request)
         elif isinstance(request, DumpRequest):
             await self._dump_buffer()
             request.set_result(None)
+        elif isinstance(request, ErrorRequest):
+            await self._save_error(request.line)
         else:
             raise UnkownRequestType
 
@@ -215,18 +231,21 @@ class Db:
     async def _initialize_mmdb(self):
         self.__mmdb = {}
         await self._load_from_file()
+        self.__file = open(self.__path, "a")
 
     async def _initialize_queue(self):
         self.__queue = asyncio.Queue()
-        self.__file = open(self.__path, "a")
         self.__buffer = StringIO()
+
+    async def _start_task(self):
         self.__task = self.__loop.create_task(self._background_task())
 
     async def _initialize(self):
         assert self.__task is None
         self.__loop = asyncio.get_event_loop()
-        await self._initialize_mmdb()
         await self._initialize_queue()
+        await self._initialize_mmdb()
+        await self._start_task()
 
     async def __aenter__(self):
         await self._initialize()