--- a/src/ast_dump.rs
+++ b/src/ast_dump.rs
@@ -199,6 +199,21 @@ impl to_string_able for expr {
             expr::GeneratorExp(elt, generators) => format!("({} {})", elt.to_string(), vec_to_strings_vec(generators).join(" ")),
             expr::Lambda(args, body) => format!("lambda {}: {}", args.to_string(), body.to_string()),
             expr::IfExp(test, body, orelse) => format!("{} if {} else {}", body.to_string(), test.to_string(), orelse.to_string()),
+            expr::Dict(keys, values) => {
+                format!("{{{}}}",
+                    {
+                        let mut items = vec!();
+                        for (key, value) in keys.iter().zip(values.iter()) {
+                            let item = match *key {
+                                None => format!("**{}", value.to_string()),
+                                Some(ref key) => format!("{}: {}", key.to_string(), value.to_string()),
+                            };
+                            items.push(item);
+                        }
+                        items.join(", ")
+                    }
+                )
+            },
         }
     }
 }