diff --git a/schala-codegen/src/lib.rs b/schala-codegen/src/lib.rs
index 0d2315d..7d5a769 100644
--- a/schala-codegen/src/lib.rs
+++ b/schala-codegen/src/lib.rs
@@ -79,7 +79,7 @@ pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream
     }
   });
 
-  let tokens = quote! {
+  let tokens: quote::Tokens = quote! {
     use schala_repl::PassDescriptor;
     impl ProgrammingLanguageInterface for #name {
       fn get_language_name(&self) -> String {
@@ -100,5 +100,6 @@ pub fn derive_programming_language_interface(input: TokenStream) -> TokenStream
     //TODO if  doc_method is defined, add code here
   };
 
-  tokens.into()
+  let output: TokenStream = tokens.into();
+  output
 }