--- a/src/ast_dump.rs
+++ b/src/ast_dump.rs
@@ -196,6 +196,7 @@ impl to_string_able for expr {
             expr::YieldFrom(value) => format!("yield from {}", value.to_string()),
             expr::Set(elts) => format!("{{{}}}", vec_to_strings_vec(elts).join(", ")),
             expr::SetComp(elt, generators) => format!("{{{} {}}}", elt.to_string(), vec_to_strings_vec(generators).join(" ")),
+            expr::GeneratorExp(elt, generators) => format!("({} {})", elt.to_string(), vec_to_strings_vec(generators).join(" ")),
         }
     }
 }