diff --git a/spec/formatting.md b/spec/formatting.md
index 6186a3995e..aae7dca597 100644
--- a/spec/formatting.md
+++ b/spec/formatting.md
@@ -324,8 +324,6 @@ The result of resolving _option_ values is a mapping of string identifiers to va
 For each _option_:
 
 - Resolve the _identifier_ of the _option_.
-- If the _option_'s _identifier_ already exists in the resolved mapping of _options_,
-   emit a _Duplicate Option Name_ error.
 - If the _option_'s right-hand side successfully resolves to a value,
    bind the _identifier_ of the _option_ to the resolved value in the mapping.
 - Otherwise, bind the _identifier_ of the _option_ to an unresolved value in the mapping.