diff --git a/src/setup/core.rs b/src/setup/core.rs
index 7f29711..e9e8a26 100644
--- a/src/setup/core.rs
+++ b/src/setup/core.rs
@@ -67,6 +67,10 @@ where
   <B as ImplementationBuilder<T>>::Implementation: Runnable + Debug,
   Self: AddGeneric<B::Prerequisites>,
   T::Artifact: Clone,
+  // These bounds cannot be replaced by
+  // `RegularSetupCore<SR, L, B>: SetupCore<T, Self>`
+  // because the prerequisites are Option<T>, too, and thus this would
+  // require AddGeneric<Option<T>> to already be implemented
 {
   async fn add_generic(&self, logger: &Rc<Logger>, r: Option<T>) -> InternalAddResult<Option<T>> {
     Ok(match r {