diff --git a/oxrlib/cache.py b/oxrlib/cache.py
index d19703201152cf1b364f1a15b350fc441438a7c1..03511d49d7f5de148ae2e9611226160bf291a97c 100644
--- a/oxrlib/cache.py
+++ b/oxrlib/cache.py
@@ -33,6 +33,10 @@ class CacheBase:
 
     def __init__(self, dir_path, **kwargs):
         self.dir_path = dir_path
+        try:
+            self.CacheFile = kwargs.pop('file_class')
+        except KeyError:
+            pass
         self.fn_patterns = {}
         self.setup(**kwargs)
 
@@ -62,3 +66,14 @@ class CacheBase:
     @_wrap_api_method
     def historical(self, date, base):
         return {'date': date.isoformat(), 'base': base}
+
+
+class WriteCacheFile(CacheFileBase):
+    ERRORS_MAP = []
+
+
+class CacheWriter(CacheBase):
+    CacheFile = WriteCacheFile
+
+    def open(self, path):
+        return self.CacheFile(path, 'w')