diff --git a/src/serve_data.js b/src/serve_data.js
index 6cff9c3..d5e61d0 100644
--- a/src/serve_data.js
+++ b/src/serve_data.js
@@ -33,9 +33,9 @@ export const serve_data = {
         return res.sendStatus(404);
       }
       const tileJSONFormat = item.tileJSON.format;
-      const z = req.params.z | 0;
-      const x = req.params.x | 0;
-      const y = req.params.y | 0;
+      const z = parseFloat(req.params.z) | 0;
+      const x = parseFloat(req.params.x) | 0;
+      const y = parseFloat(req.params.y) | 0;
       let format = req.params.format;
       if (format === options.pbfAlias) {
         format = 'pbf';