diff --git a/src/items/external-blocks.md b/src/items/external-blocks.md
index 7ff995bd8..bd3830661 100644
--- a/src/items/external-blocks.md
+++ b/src/items/external-blocks.md
@@ -17,7 +17,7 @@
 >
 > _ExternalFunctionItem_ :\
 > &nbsp;&nbsp; `fn` [IDENTIFIER]&nbsp;[_Generics_]<sup>?</sup>\
-> &nbsp;&nbsp; `(` _NamedFunctionParameters_<sup>?</sup> | _NamedFunctionParametersWithVariadics_ ) `)`\
+> &nbsp;&nbsp; `(` ( _NamedFunctionParameters_ | _NamedFunctionParametersWithVariadics_ )<sup>?</sup> `)`\
 > &nbsp;&nbsp; [_FunctionReturnType_]<sup>?</sup> [_WhereClause_]<sup>?</sup> `;`
 >
 > _NamedFunctionParameters_ :\