diff --git a/notice/api/3.0.md b/notice/api/3.0.md
index 143a313..e41e172 100644
--- a/notice/api/3.0.md
+++ b/notice/api/3.0.md
@@ -324,7 +324,7 @@ Each method is represented as a class' method with the same name as the associat
 Arguments are passed to the method as a single argument which an associative array according to the configuration.
 
 _Notes_:
-* Optional parameters if not given are set to their default value (cf. [parameter.optional](#parameterisoptional), [parameter.default_value](#parameterdefault_value))
+* Optional parameters if not given are set to their default value (cf. [parameter.optional](#parameteris_optional), [parameter.default_value](#parameterdefault_value))
 * parameters of type `FILE` are given by reference but the use is the same as normal parameters (cf. [complex types](#2---complex-types))
 * URI parameters are called `URL0`, `URL1` and so on according to their order if no `rename` set in the configuration. (cf: [parameter.name](#parametername), [parameter.rename](#parameterrename))