diff --git a/schala-lang/language/src/parser.rs b/schala-lang/language/src/parser.rs
index e7db2fc..74c98b8 100644
--- a/schala-lang/language/src/parser.rs
+++ b/schala-lang/language/src/parser.rs
@@ -17,11 +17,9 @@ use crate::builtin::Builtin;
 
 type ParseResult<'a, T> = IResult<&'a str, T, VerboseError<&'a str>>;
 
-pub fn ws<I, O, E: ParseError<I>, F>(parser: F) -> impl Fn(I) -> IResult<I, O, E>
+pub fn ws<'a, O, E: ParseError<&'a str>, F>(parser: F) -> impl Fn(&'a str) -> IResult<&'a str, O, E>
 where
-    I: nom::InputTakeAtPosition,
-    <I as nom::InputTakeAtPosition>::Item: nom::AsChar + Clone,
-    F: Fn(I) -> IResult<I, O, E>,
+    F: Fn(&'a str) -> IResult<&'a str, O, E>,
     {
       delimited(space0, parser, space0)
     }