--- a/src/ast_dump.rs
+++ b/src/ast_dump.rs
@@ -243,7 +243,14 @@ impl stmt {
                     decorator_list_to_string(decorator_list, indent),
                     current_indent,
                     name,
-                    vec_to_strings_vec(bases).join(", "),
+                    {
+                        let mut arguments = vec!();
+                        let bases = vec_to_strings_vec(bases);
+                        let keywords = vec_to_strings_vec(keywords);
+                        arguments.extend(bases);
+                        arguments.extend(keywords);
+                        arguments.join(", ")
+                    },
                     statements_to_string(indent, body)
                 )
             },