diff --git a/app/alias_suffix.py b/app/alias_suffix.py
index 40c54622..6a2c69e8 100644
--- a/app/alias_suffix.py
+++ b/app/alias_suffix.py
@@ -162,8 +162,6 @@ def get_alias_suffixes(
             or user.default_alias_public_domain_id != sl_domain.id
         ):
             alias_suffixes.append(alias_suffix)
-            # If no default domain mark it as found
-            default_domain_found = user.default_alias_public_domain_id is None
         else:
             default_domain_found = True
             alias_suffixes.insert(0, alias_suffix)
diff --git a/tests/test_alias_suffixes.py b/tests/test_alias_suffixes.py
index 9706a13e..870baa16 100644
--- a/tests/test_alias_suffixes.py
+++ b/tests/test_alias_suffixes.py
@@ -131,3 +131,22 @@ def test_suffixes_are_valid():
         if len(match.groups()) >= 1:
             has_prefix += 1
     assert has_prefix > 0
+
+
+def test_get_default_domain_is_only_shown_once():
+    user = create_new_user()
+    default_domain = SLDomain.filter_by(hidden=False).order_by(SLDomain.order).first()
+    user.default_alias_public_domain_id = default_domain.id
+    Session.flush()
+    options = AliasOptions(
+        show_sl_domains=True, show_partner_domains=get_proton_partner()
+    )
+    suffixes = get_alias_suffixes(user, alias_options=options)
+    found_default = False
+    found_domains = set()
+    for suffix in suffixes:
+        assert suffix.domain not in found_domains
+        found_domains.add(suffix.domain)
+        if default_domain.domain == suffix.domain:
+            found_default = True
+    assert found_default