diff --git a/core/meta.py b/core/meta.py
index fcab821..683265e 100644
--- a/core/meta.py
+++ b/core/meta.py
@@ -1,3 +1,4 @@
+from datetime import datetime
 from enum import Enum
 from enum import unique
 from typing import Any
@@ -47,6 +48,10 @@ def _meta(mk: MetaKey) -> str:
     return f"meta.{mk.value}"
 
 
+def flag(mk: MetaKey, val: Any) -> _SubQuery:
+    return {_meta(mk): val}
+
+
 def by_remote_id(remote_id: str) -> _SubQuery:
     return {"remote_id": remote_id}
 
@@ -64,23 +69,23 @@ def by_type(type_: ap.ActivityType) -> _SubQuery:
 
 
 def not_undo() -> _SubQuery:
-    return {_meta(MetaKey.UNDO): False}
+    return flag(MetaKey.UNDO, False)
 
 
 def by_actor(actor: ap.BaseActivity) -> _SubQuery:
-    return {_meta(MetaKey.ACTOR_ID): actor.id}
+    return flag(MetaKey.ACTOR_ID, actor.id)
 
 
 def by_object_id(object_id: str) -> _SubQuery:
-    return {_meta(MetaKey.OBJECT_ID): object_id}
+    return flag(MetaKey.OBJECT_ID, object_id)
 
 
 def is_public() -> _SubQuery:
-    return {_meta(MetaKey.PUBLIC): True}
+    return flag(MetaKey.PUBLIC, True)
 
 
 def inc(mk: MetaKey, val: int) -> _SubQuery:
-    return {"$inc": {_meta(mk): val}}
+    return {"$inc": flag(mk, val)}
 
 
 def upsert(data: Dict[MetaKey, Any]) -> _SubQuery:
@@ -92,5 +97,5 @@ def upsert(data: Dict[MetaKey, Any]) -> _SubQuery:
     return {"$set": sq}
 
 
-def flag(mk: MetaKey, val: Any) -> _SubQuery:
-    return {_meta(mk): val}
+def published_after(dt: datetime) -> _SubQuery:
+    return flag(MetaKey.PUBLISHED, {"gt": ap.format(dt)})
diff --git a/core/notifications.py b/core/notifications.py
index 977acb2..614b090 100644
--- a/core/notifications.py
+++ b/core/notifications.py
@@ -1,4 +1,7 @@
 import logging
+from datetime import datetime
+from datetime import timedelta
+from datetime import timezone
 from functools import singledispatch
 from typing import Any
 from typing import Dict
@@ -8,12 +11,16 @@ from little_boxes import activitypub as ap
 
 from config import BASE_URL
 from config import DB
+from core.db import find_one_activity
 from core.meta import MetaKey
 from core.meta import _meta
 from core.meta import by_actor
+from core.meta import by_object_id
 from core.meta import by_type
+from core.meta import flag
 from core.meta import in_inbox
 from core.meta import not_undo
+from core.meta import published_after
 from core.tasks import Tasks
 
 _logger = logging.getLogger(__name__)
@@ -123,16 +130,26 @@ def _like_set_inbox_flags(activity: ap.Like, new_meta: _NewMeta) -> None:
 @set_inbox_flags.register
 def _announce_set_inbox_flags(activity: ap.Announce, new_meta: _NewMeta) -> None:
     _logger.info(f"set_inbox_flags activity={activity!r}")
-    # Is it a Like of local acitivty/from the outbox
-    if _is_from_outbox(activity.get_object()):
+    obj = activity.get_object()
+    # Is it a Annnounce/boost of local acitivty/from the outbox
+    if _is_from_outbox(obj):
         # Flag it as a notification
         _flag_as_notification(activity, new_meta)
 
         # Also set the "keep mark" for the GC (as we want to keep it forever)
         _set_flag(new_meta, MetaKey.GC_KEEP)
 
-    # Display it in the stream
-    _set_flag(new_meta, MetaKey.STREAM)
+    # Dedup boosts (it's annoying to see the same note multipe times on the same page)
+    if not find_one_activity(
+        {
+            **in_inbox(),
+            **by_object_id(obj.id),
+            **flag(MetaKey.STREAM, True),
+            **published_after(datetime.now(timezone.utc) - timedelta(hours=12)),
+        }
+    ):
+        # Display it in the stream only it not there already (only looking at the last 12 hours)
+        _set_flag(new_meta, MetaKey.STREAM)
 
     return None