diff --git a/camdetect.py b/camdetect.py
index 79abad5..251ef30 100755
--- a/camdetect.py
+++ b/camdetect.py
@@ -51,6 +51,7 @@ SOURCE_NAME = os.environ["SOURCE_NAME"]
 SLIDE_WINDOW = 2
 DCT_BLOCK_SIZE = 8
 UPLOAD_FRAMESKIP = 3
+CLOCK_SKEW_TOLERANCE = timedelta(seconds=3)
 
 # Percentage of blocks active to consider movement in whole frame
 THRESHOLD_RATIO = int(os.getenv("THRESHOLD_RATIO", "5"))
@@ -273,11 +274,14 @@ async def motion_detector(reference_frame, download_queue, upload_queue):
         # Handle event start
         if motion_detected and not event_id:
             result = await app.ctx.coll.find_one_and_update({
-                "timestamp": dt,  # TODO: Account for clock skew
+                "@timestamp": {
+                    "$lte": dt + CLOCK_SKEW_TOLERANCE,
+                    "$gte": dt - CLOCK_SKEW_TOLERANCE,
+                },
                 "source": SOURCE_NAME,
             }, {
                 "$setOnInsert": {
-                    "timestamp": dt,
+                    "@timestamp": dt,
                     "source": SOURCE_NAME,
                     "event": "motion-detected",
                     "started": dt,
@@ -552,8 +556,10 @@ async def setup_db(app, loop):
     app.ctx.db = AsyncIOMotorClient(MONGO_URI).get_default_database()
     app.ctx.coll = app.ctx.db[MONGO_COLLECTION]
     app.ctx.coll.create_index([
-        ("timestamp", pymongo.ASCENDING),
-        ("source", pymongo.ASCENDING)], unique=True)
+        ("@timestamp", pymongo.ASCENDING)])
+    app.ctx.coll.create_index([
+        ("source", pymongo.ASCENDING),
+        ("@timestamp", pymongo.ASCENDING)], unique=True)
     app.ctx.last_frame = None
     app.ctx.event_frame = asyncio.Event()
     app.ctx.event_id = None