diff --git a/maloja/apis/native_v1.py b/maloja/apis/native_v1.py
index aea7710..7a90501 100644
--- a/maloja/apis/native_v1.py
+++ b/maloja/apis/native_v1.py
@@ -82,6 +82,14 @@ errors = {
 			'desc':"This entity does not exist in the database."
 		}
 	}),
+	database.exceptions.DuplicateTimestamp: lambda e: (409,{
+		"status":"error",
+		"error":{
+			'type':'duplicate_timestamp',
+			'value':e.rejected_scrobble,
+			'desc':"A scrobble is already registered with this timestamp."
+		}
+	}),
 	images.MalformedB64: lambda e: (400,{
 		"status":"failure",
 		"error":{
diff --git a/maloja/database/exceptions.py b/maloja/database/exceptions.py
index 534dc1e..47abbd4 100644
--- a/maloja/database/exceptions.py
+++ b/maloja/database/exceptions.py
@@ -14,6 +14,13 @@ class ArtistExists(EntityExists):
 class AlbumExists(EntityExists):
 	pass
 
+
+class DuplicateTimestamp(Exception):
+	def __init__(self,existing_scrobble,rejected_scrobble):
+		self.existing_scrobble = existing_scrobble
+		self.rejected_scrobble = rejected_scrobble
+
+
 class DatabaseNotBuilt(HTTPError):
 	def __init__(self):
 		super().__init__(
diff --git a/maloja/database/sqldb.py b/maloja/database/sqldb.py
index 5dce8a0..2641c66 100644
--- a/maloja/database/sqldb.py
+++ b/maloja/database/sqldb.py
@@ -328,7 +328,10 @@ def album_dict_to_db(info,dbconn=None):
 
 @connection_provider
 def add_scrobble(scrobbledict,update_album=False,dbconn=None):
-	add_scrobbles([scrobbledict],update_album=update_album,dbconn=dbconn)
+	_, e = add_scrobbles([scrobbledict],update_album=update_album,dbconn=dbconn)
+	if e > 0:
+		raise exc.DuplicateTimestamp(existing_scrobble=None,rejected_scrobble=scrobbledict)
+		# TODO: actually pass existing scrobble
 
 @connection_provider
 def add_scrobbles(scrobbleslist,update_album=False,dbconn=None):