diff --git a/src/sphinxcontrib/bibtex/style/referencing/basic_super.py b/src/sphinxcontrib/bibtex/style/referencing/basic_super.py
index 7b8d6922..5405468f 100644
--- a/src/sphinxcontrib/bibtex/style/referencing/basic_super.py
+++ b/src/sphinxcontrib/bibtex/style/referencing/basic_super.py
@@ -45,9 +45,12 @@ def role_names(self) -> Iterable[str]:
         ]
 
     def outer(self, role_name: str, children: List["BaseText"]) -> "Node":
-        return tag("sup")[
-            self.bracket.outer(children, brackets="al" not in role_name, capfirst=False)
-        ]
+        if "al" not in role_name:
+            return tag("sup")[
+                self.bracket.outer(children, brackets=True, capfirst=False)
+            ]
+        else:
+            self.bracket.outer(children, brackets=False, capfirst=False)
 
     def inner(self, role_name: str) -> "Node":
         return join2(sep1=self.pre_text_sep, sep2=self.post_text_sep)[