1 files changed, 6 insertions, 2 deletions
diff --git a/src/leaflet-soton.js b/src/leaflet-soton.js
index 0948789..ba5a138 100644
--- a/src/leaflet-soton.js
+++ b/src/leaflet-soton.js
@@ -1746,8 +1746,12 @@ SELECT * WHERE {\
 
         xhttp.send(options.data);
         xhttp.onreadystatechange = function() {
-            if (xhttp.status == 200 && xhttp.readyState == 4) {
-                callback(JSON.parse(xhttp.responseText), xhttp.responseText);
+            if (xhttp.readyState === 4) { // loaded
+                if (xhttp.status === 200) {
+                    callback(JSON.parse(xhttp.responseText), xhttp.responseText);
+                } else {
+                    callback(null);
+                }
             }
         };
     }