diff --git a/vdirsyncer/sync/__init__.py b/vdirsyncer/sync/__init__.py
index 9e3fec1..25b46a3 100644
--- a/vdirsyncer/sync/__init__.py
+++ b/vdirsyncer/sync/__init__.py
@@ -296,7 +296,7 @@ class ResolveConflict(Action):
                 )
 
 
-def _get_actions(a_info, b_info):
+def _get_actions(a_info: _StorageInfo, b_info: _StorageInfo):
     for ident in uniq(
         itertools.chain(
             a_info.status.parent.iter_new(), a_info.status.parent.iter_old()
diff --git a/vdirsyncer/sync/status.py b/vdirsyncer/sync/status.py
index 7d246b8..1f3f910 100644
--- a/vdirsyncer/sync/status.py
+++ b/vdirsyncer/sync/status.py
@@ -328,7 +328,7 @@ class SqliteStatus(_StatusBase):
 
 
 class SubStatus:
-    def __init__(self, parent, side):
+    def __init__(self, parent: SqliteStatus, side: str):
         self.parent = parent
         assert side in "ab"