diff --git a/tests/__init__.py b/tests/__init__.py
index 1f491f7..1d754a6 100644
--- a/tests/__init__.py
+++ b/tests/__init__.py
@@ -41,7 +41,7 @@ TEL;TYPE=VOICE:412 605 0499
 TEL;TYPE=FAX:412 605 0705
 URL:http://www.example.com
 X-SOMETHING:{r}
-UID:{r}
+UID:{uid}
 END:VCARD'''
 
 TASK_TEMPLATE = u'''BEGIN:VCALENDAR
@@ -54,7 +54,7 @@ LAST-MODIFIED;VALUE=DATE-TIME:20140122T151338Z
 SEQUENCE:2
 SUMMARY:Book: Kowlani - Tödlicher Staub
 X-SOMETHING:{r}
-UID:{r}
+UID:{uid}
 END:VTODO
 END:VCALENDAR'''
 
@@ -64,7 +64,7 @@ DTSTART:19970714T170000Z
 DTEND:19970715T035959Z
 SUMMARY:Bastille Day Party
 X-SOMETHING:{r}
-UID:{r}
+UID:{uid}
 END:VEVENT'''
 
 
@@ -76,7 +76,7 @@ END:VCALENDAR'''
 
 
 SIMPLE_TEMPLATE = u'''BEGIN:FOO
-UID:{r}
+UID:{uid}
 X-SOMETHING:{r}
 HAHA:YES
 END:FOO'''
diff --git a/tests/storage/__init__.py b/tests/storage/__init__.py
index 3376cb5..1dcdcac 100644
--- a/tests/storage/__init__.py
+++ b/tests/storage/__init__.py
@@ -19,10 +19,10 @@ from .. import EVENT_TEMPLATE, TASK_TEMPLATE, VCARD_TEMPLATE, \
     assert_item_equals
 
 
-def format_item(item_template):
+def format_item(item_template, uid=None):
     # assert that special chars are handled correctly.
     r = '{}@vdirsyncer'.format(random.random())
-    return Item(item_template.format(r=r))
+    return Item(item_template.format(r=r, uid=uid or r))
 
 
 class StorageTests(object):
@@ -45,7 +45,7 @@ class StorageTests(object):
 
     @pytest.fixture
     def get_item(self, item_template):
-        return lambda: format_item(item_template)
+        return lambda **kw: format_item(item_template, **kw)
 
     @pytest.fixture
     def requires_collections(self):
@@ -91,7 +91,7 @@ class StorageTests(object):
         href, etag = s.upload(item)
         assert_item_equals(s.get(href)[0], item)
 
-        new_item = get_item()
+        new_item = get_item(uid=item.uid)
         new_etag = s.update(href, new_item, etag)
         # See https://github.com/untitaker/vdirsyncer/issues/48
         assert isinstance(new_etag, (bytes, text_type))
diff --git a/tests/utils/test_vobject.py b/tests/utils/test_vobject.py
index bf10a50..a29dd66 100644
--- a/tests/utils/test_vobject.py
+++ b/tests/utils/test_vobject.py
@@ -18,9 +18,9 @@ from .. import BARE_EVENT_TEMPLATE, EVENT_TEMPLATE, VCARD_TEMPLATE, \
     normalize_item
 
 _simple_split = [
-    VCARD_TEMPLATE.format(r=123),
-    VCARD_TEMPLATE.format(r=345),
-    VCARD_TEMPLATE.format(r=678)
+    VCARD_TEMPLATE.format(r=123, uid=123),
+    VCARD_TEMPLATE.format(r=345, uid=345),
+    VCARD_TEMPLATE.format(r=678, uid=678)
 ]
 
 _simple_joined = u'\r\n'.join(
@@ -115,8 +115,8 @@ def test_join_collection_vevents():
 
 def test_split_collection_timezones():
     items = [
-        BARE_EVENT_TEMPLATE.format(r=123),
-        BARE_EVENT_TEMPLATE.format(r=345)
+        BARE_EVENT_TEMPLATE.format(r=123, uid=123),
+        BARE_EVENT_TEMPLATE.format(r=345, uid=345)
     ]
 
     timezone = (
@@ -151,7 +151,7 @@ def test_split_collection_timezones():
 
 
 def test_hash_item():
-    a = EVENT_TEMPLATE.format(r=1)
+    a = EVENT_TEMPLATE.format(r=1, uid=1)
     b = u'\n'.join(line for line in a.splitlines()
                    if u'PRODID' not in line and u'VERSION' not in line)
     assert vobject.hash_item(a) == vobject.hash_item(b)