diff --git a/backend/src/main/resources/db/migration/V50__backfill_comment_audit_events.sql b/backend/src/main/resources/db/migration/V50__backfill_comment_audit_events.sql
new file mode 100644
index 00000000..839682a1
--- /dev/null
+++ b/backend/src/main/resources/db/migration/V50__backfill_comment_audit_events.sql
@@ -0,0 +1,39 @@
+-- Backfill COMMENT_ADDED and MENTION_CREATED audit events for comments
+-- created before audit logging was added in commit 428c63a2.
+-- Without these rows the Chronik activity feed (which reads exclusively from
+-- audit_log) cannot surface pre-existing comments in "Für dich" or "Alle".
+
+INSERT INTO audit_log (id, happened_at, actor_id, kind, document_id, payload)
+SELECT
+    gen_random_uuid(),
+    c.created_at,
+    c.author_id,
+    'COMMENT_ADDED',
+    c.document_id,
+    jsonb_build_object('commentId', c.id::text)
+FROM document_comments c
+WHERE NOT EXISTS (
+    SELECT 1 FROM audit_log a
+    WHERE a.kind = 'COMMENT_ADDED'
+      AND a.payload->>'commentId' = c.id::text
+);
+
+INSERT INTO audit_log (id, happened_at, actor_id, kind, document_id, payload)
+SELECT
+    gen_random_uuid(),
+    c.created_at,
+    c.author_id,
+    'MENTION_CREATED',
+    c.document_id,
+    jsonb_build_object(
+        'commentId', c.id::text,
+        'mentionedUserId', m.user_id::text
+    )
+FROM comment_mentions m
+JOIN document_comments c ON c.id = m.comment_id
+WHERE NOT EXISTS (
+    SELECT 1 FROM audit_log a
+    WHERE a.kind = 'MENTION_CREATED'
+      AND a.payload->>'commentId' = c.id::text
+      AND a.payload->>'mentionedUserId' = m.user_id::text
+);