diff --git a/src/Mastodon/Helper.elm b/src/Mastodon/Helper.elm
index bd96e84..95e9f9a 100644
--- a/src/Mastodon/Helper.elm
+++ b/src/Mastodon/Helper.elm
@@ -6,7 +6,7 @@ module Mastodon.Helper
         , notificationToAggregate
         )
 
-import List.Extra exposing (groupWhile)
+import List.Extra exposing (groupWhile, uniqueBy)
 import Mastodon.Model
     exposing
         ( Notification
@@ -114,7 +114,7 @@ aggregateNotifications notifications =
         extractAggregate statusGroup =
             let
                 accounts =
-                    List.map .account statusGroup
+                    statusGroup |> List.map .account |> uniqueBy .id
             in
                 case statusGroup of
                     notification :: _ ->
diff --git a/tests/Fixtures.elm b/tests/Fixtures.elm
index b18eaf9..40010d0 100644
--- a/tests/Fixtures.elm
+++ b/tests/Fixtures.elm
@@ -198,6 +198,14 @@ notifications =
     ]
 
 
+duplicateAccountNotifications : List Notification
+duplicateAccountNotifications =
+    [ notificationSkroFollowsVjousse
+    , notificationSkroFollowsVjousse
+    , notificationSkroFollowsVjousse
+    ]
+
+
 notificationAggregates : List NotificationAggregate
 notificationAggregates =
     [ { type_ = "mention"
diff --git a/tests/MastodonTest/HelperTest.elm b/tests/MastodonTest/HelperTest.elm
index 6b1efcc..d927e99 100644
--- a/tests/MastodonTest/HelperTest.elm
+++ b/tests/MastodonTest/HelperTest.elm
@@ -26,6 +26,12 @@ all =
                               , created_at = "2017-04-24T20:13:47.431Z"
                               }
                             ]
+            , test "Dedupes aggregated accounts" <|
+                \() ->
+                    Fixtures.duplicateAccountNotifications
+                        |> Mastodon.Helper.aggregateNotifications
+                        |> List.map (.accounts >> List.length)
+                        |> Expect.equal [ 1 ]
             , test "Add follows notification to aggregate" <|
                 \() ->
                     Fixtures.notifications