diff --git a/src/layers.rs b/src/layers.rs
index 2b2a6c3a4ce3441e44f7f252c9006ffc75462bcd..955c715cfc78bba7ce223b71340b2540e015e0b4 100644
--- a/src/layers.rs
+++ b/src/layers.rs
@@ -75,7 +75,7 @@ impl Layer {
             ],
             required: [
                 ("name", name, |v| Some(v)),
-                ("id", id, |v:String| v.parse::<u32>().ok()),
+                ("id", id, |v:String| v.parse().ok()),
             ],
             TiledError::MalformedAttributes("layer must have a name".to_string())
         );
diff --git a/src/objects.rs b/src/objects.rs
index 36dcd6a1dd928267e94233dc0029d73555547303..05219236d635c0610b01066e55f12bbfb984ef20 100644
--- a/src/objects.rs
+++ b/src/objects.rs
@@ -38,7 +38,7 @@ impl ObjectGroup {
                 ("name", name, |v:String| v.into()),
             ],
             required: [
-                ("id", id, |v:String| v.parse::<u32>().ok()),
+                ("id", id, |v:String| v.parse().ok()),
             ],
             TiledError::MalformedAttributes("object groups must have a name".to_string())
         );