diff --git a/tests/storage/__init__.py b/tests/storage/__init__.py
index 141212c..b72655a 100644
--- a/tests/storage/__init__.py
+++ b/tests/storage/__init__.py
@@ -236,6 +236,8 @@ class StorageTests(object):
 
     def test_metadata(self, requires_metadata, s):
         try:
+            s.set_meta('color', None)
+            assert s.get_meta('color') is None
             s.set_meta('color', u'#ff0000')
             assert s.get_meta('color') == u'#ff0000'
         except exceptions.UnsupportedMetadataError:
diff --git a/tests/test_metasync.py b/tests/test_metasync.py
new file mode 100644
index 0000000..e0bbaec
--- /dev/null
+++ b/tests/test_metasync.py
@@ -0,0 +1,77 @@
+# -*- coding: utf-8 -*-
+
+import pytest
+
+import vdirsyncer.exceptions as exceptions
+from vdirsyncer.storage.base import Item
+from vdirsyncer.storage.memory import MemoryStorage
+from vdirsyncer.metasync import metasync, MetaSyncConflict
+
+from . import assert_item_equals, blow_up, normalize_item
+
+def test_irrelevant_status():
+    a = MemoryStorage()
+    b = MemoryStorage()
+    status = {'foo': 'bar'}
+
+    metasync(a, b, status, keys=())
+    assert not status
+
+def test_basic():
+    a = MemoryStorage()
+    b = MemoryStorage()
+    status = {}
+
+    a.set_meta('foo', 'bar')
+    metasync(a, b, status, keys=['foo'])
+    assert a.get_meta('foo') == b.get_meta('foo') == 'bar'
+
+    a.set_meta('foo', 'baz')
+    metasync(a, b, status, keys=['foo'])
+    assert a.get_meta('foo') == b.get_meta('foo') == 'baz'
+
+    b.set_meta('foo', None)
+    metasync(a, b, status, keys=['foo'])
+    assert a.get_meta('foo') is b.get_meta('foo') is None
+
+
+def test_conflict():
+    a = MemoryStorage()
+    b = MemoryStorage()
+    status = {}
+    a.set_meta('foo', 'bar')
+    b.set_meta('foo', 'baz')
+
+    with pytest.raises(MetaSyncConflict):
+        metasync(a, b, status, keys=['foo'])
+
+    assert a.get_meta('foo') == 'bar'
+    assert b.get_meta('foo') == 'baz'
+    assert not status
+
+
+def test_conflict_same_content():
+    a = MemoryStorage()
+    b = MemoryStorage()
+    status = {}
+    a.set_meta('foo', 'bar')
+    b.set_meta('foo', 'bar')
+
+    metasync(a, b, status, keys=['foo'])
+    assert a.get_meta('foo') == b.get_meta('foo') == status['foo'] == 'bar'
+
+
+@pytest.mark.parametrize('wins', 'ab')
+def test_conflict_x_wins(wins):
+    a = MemoryStorage()
+    b = MemoryStorage()
+    status = {}
+    a.set_meta('foo', 'bar')
+    b.set_meta('foo', 'baz')
+
+    metasync(a, b, status, keys=['foo'],
+             conflict_resolution='a wins' if wins == 'a' else 'b wins')
+
+    assert a.get_meta('foo') == b.get_meta('foo') == status['foo'] == (
+        'bar' if wins == 'a' else 'baz'
+    )
diff --git a/vdirsyncer/metasync.py b/vdirsyncer/metasync.py
index c0d88b2..db7ce74 100644
--- a/vdirsyncer/metasync.py
+++ b/vdirsyncer/metasync.py
@@ -11,7 +11,7 @@ class MetaSyncConflict(MetaSyncError):
     key = None
 
 
-def metasync(storage_a, storage_b, status, keys, conflict_resolution):
+def metasync(storage_a, storage_b, status, keys, conflict_resolution=None):
     def _a_to_b():
         logger.info(u'Copying {} to {}'.format(key, storage_b))
         storage_b.set_meta(key, a)
@@ -24,7 +24,7 @@ def metasync(storage_a, storage_b, status, keys, conflict_resolution):
 
     def _resolve_conflict():
         if a == b:
-            pass
+            status[key] = a
         elif conflict_resolution is None:
             raise MetaSyncConflict(key=key)
         elif conflict_resolution == 'a wins':
diff --git a/vdirsyncer/storage/filesystem.py b/vdirsyncer/storage/filesystem.py
index 543d863..7b844ae 100644
--- a/vdirsyncer/storage/filesystem.py
+++ b/vdirsyncer/storage/filesystem.py
@@ -185,7 +185,7 @@ class FilesystemStorage(Storage):
         fpath = os.path.join(self.path, key)
         try:
             with open(fpath, 'rb') as f:
-                return f.read().decode(self.encoding)
+                return f.read().decode(self.encoding) or None
         except IOError as e:
             if e.errno == errno.ENOENT:
                 return None
@@ -193,6 +193,7 @@ class FilesystemStorage(Storage):
                 raise
 
     def set_meta(self, key, value):
+        value = value or u''
         assert isinstance(value, text_type)
         fpath = os.path.join(self.path, key)
         with atomic_write(fpath, mode='wb', overwrite=True) as f:
diff --git a/vdirsyncer/storage/memory.py b/vdirsyncer/storage/memory.py
index 2775745..6a01c00 100644
--- a/vdirsyncer/storage/memory.py
+++ b/vdirsyncer/storage/memory.py
@@ -66,7 +66,7 @@ class MemoryStorage(Storage):
         del self.items[href]
 
     def get_meta(self, key):
-        return self.metadata[key]
+        return self.metadata.get(key)
 
     def set_meta(self, key, value):
         self.metadata[key] = value