diff --git a/async-graphql-derive/src/interface.rs b/async-graphql-derive/src/interface.rs
index 82c5d6a2..b52e49ad 100644
--- a/async-graphql-derive/src/interface.rs
+++ b/async-graphql-derive/src/interface.rs
@@ -64,7 +64,7 @@ pub fn generate(interface_args: &args::Interface, input: &DeriveInput) -> Result
                     if let #ident::#enum_name(obj) = self {
                         return #crate_name::collect_fields(ctx, obj, futures);
                     }
-                    unreachable!()
+                    return Ok(());
                 }
             });
             get_introspection_typename.push(quote! {
diff --git a/async-graphql-derive/src/union.rs b/async-graphql-derive/src/union.rs
index 61e9a4c4..28f8cc9c 100644
--- a/async-graphql-derive/src/union.rs
+++ b/async-graphql-derive/src/union.rs
@@ -60,7 +60,7 @@ pub fn generate(interface_args: &args::Interface, input: &DeriveInput) -> Result
                     if let #ident::#enum_name(obj) = self {
                         return #crate_name::collect_fields(ctx, obj, futures);
                     }
-                    unreachable!()
+                    return Ok(());
                 }
             });
             get_introspection_typename.push(quote! {