diff --git a/src/libstd/json.rs b/src/libstd/json.rs
index 1ac6a5476597803be7cf5c85213f6757646456e8..a5a5ac310354009aa7b65ffc844bb69239689cd3 100644
--- a/src/libstd/json.rs
+++ b/src/libstd/json.rs
@@ -510,6 +510,14 @@ impl of to_json for json {
     fn to_json() -> json { self }
 }
 
+impl of to_json for @json {
+    fn to_json() -> json { *self }
+}
+
+impl of to_json for int {
+    fn to_json() -> json { num(self as float) }
+}
+
 impl of to_json for i8 {
     fn to_json() -> json { num(self as float) }
 }
@@ -526,6 +534,10 @@ impl of to_json for i64 {
     fn to_json() -> json { num(self as float) }
 }
 
+impl of to_json for uint {
+    fn to_json() -> json { num(self as float) }
+}
+
 impl of to_json for u8 {
     fn to_json() -> json { num(self as float) }
 }