diff --git a/crates/rmcp-macros/src/prompt.rs b/crates/rmcp-macros/src/prompt.rs
index 20492a66..f8e1e886 100644
--- a/crates/rmcp-macros/src/prompt.rs
+++ b/crates/rmcp-macros/src/prompt.rs
@@ -138,10 +138,18 @@ pub fn prompt(attr: TokenStream, input: TokenStream) -> syn::Result<TokenStream>
             }
             match &fn_item.sig.output {
                 syn::ReturnType::Default => {
-                    quote! { -> ::std::pin::Pin<Box<dyn ::std::future::Future<Output = ()> + Send + #lt>> }
+                    if omit_send {
+                        quote! { -> ::std::pin::Pin<Box<dyn ::std::future::Future<Output = ()> + #lt>> }
+                    } else {
+                        quote! { -> ::std::pin::Pin<Box<dyn ::std::future::Future<Output = ()> + Send + #lt>> }
+                    }
                 }
                 syn::ReturnType::Type(_, ty) => {
-                    quote! { -> ::std::pin::Pin<Box<dyn ::std::future::Future<Output = #ty> + Send + #lt>> }
+                    if omit_send {
+                        quote! { -> ::std::pin::Pin<Box<dyn ::std::future::Future<Output = #ty> + #lt>> }
+                    } else {
+                        quote! { -> ::std::pin::Pin<Box<dyn ::std::future::Future<Output = #ty> + Send + #lt>> }
+                    }
                 }
             }
         })?;