diff --git a/lib/gltfPrimitiveToCesiumGeometry.js b/lib/gltfPrimitiveToCesiumGeometry.js
index c3cf4908..4ce5d5bd 100644
--- a/lib/gltfPrimitiveToCesiumGeometry.js
+++ b/lib/gltfPrimitiveToCesiumGeometry.js
@@ -15,10 +15,11 @@ module.exports = gltfPrimitiveToCesiumGeometry;
 function unpackArray(values) {
     var length = values.data.length;
     var packed;
+    var i;
     switch (values.type) {
         case 'Cartesian2':
             packed = new Array(length * 2);
-            for (var i = 0; i < length; ++i) {
+            for (i = 0; i < length; ++i) {
                 Cartesian2.pack(values.data[i], packed, i * 2);
             }
             return packed;