diff --git a/mastodon/models/mastodon.py b/mastodon/models/mastodon.py
index e15a6cef..e6012016 100644
--- a/mastodon/models/mastodon.py
+++ b/mastodon/models/mastodon.py
@@ -592,6 +592,17 @@ def authenticate(domain, access_token, refresh_token) -> "MastodonAccount | None
                 uid=mastodon_account.uid,
                 domain=mastodon_account.domain,
             ).first()
+            if not existing_account:
+                existing_account = MastodonAccount.objects.filter(
+                    handle=mastodon_account.handle,
+                    domain=mastodon_account.domain,
+                ).first()
+                if existing_account:
+                    # this is only needed if server is Firefish
+                    logger.warning(
+                        f"USER ID CHANGED: {existing_account.uid} -> {mastodon_account.uid} for {existing_account.handle}"
+                    )
+                    existing_account.uid = mastodon_account.uid
             if existing_account:
                 existing_account.access_token = mastodon_account.access_token
                 existing_account.refresh_token = mastodon_account.refresh_token