diff --git a/runtime/gdev/tests/common/mod.rs b/runtime/gdev/tests/common/mod.rs
index 2ad0ff20597c85721fc5e01e47676a5fdbc15c53..673a02252b3a90ce92af5d91e6c16940a5666c00 100644
--- a/runtime/gdev/tests/common/mod.rs
+++ b/runtime/gdev/tests/common/mod.rs
@@ -142,7 +142,7 @@ impl ExtBuilder {
     }*/
 
     pub fn change_parameters<
-        F: Fn(&mut pallet_duniter_test_parameters::Parameters<u32, u32, Balance>) -> (),
+        F: Fn(&mut pallet_duniter_test_parameters::Parameters<u32, u32, Balance>),
     >(
         mut self,
         f: F,