diff --git a/demo/extractmesh.c b/demo/extractmesh.c
index 4ee0243..7126d2d 100644
--- a/demo/extractmesh.c
+++ b/demo/extractmesh.c
@@ -25,22 +25,22 @@ void writemesh(const struct MeshHeader *mh,
 
     // batch data the same treatment.
     struct BatchData * newBatches = malloc(newmh.numBatch * sizeof(struct BatchData));
-    uint64_t previousBatch = 0;
+    uint64_t endOfPrevious = 0;
     for (int i = 0; i < newmh.numBatch; i++) {
       newBatches[i] = (m -> b) -> bd[i];
       unsigned int nVertices = m -> b -> bd[i].numVertex;
-      if (previousBatch == 0) {
+      if (endOfPrevious == 0) {
         newBatches[i].offsetPositions = newmh.offsetBatches + ( newmh.numBatch * sizeof(struct BatchData));
       }
       else {
-        newBatches[i].offsetPositions = previousBatch;
+        newBatches[i].offsetPositions = endOfPrevious;
       }
       newBatches[i].offsetNormals     = newBatches[i].offsetPositions   + (sizeof(struct Coordinate)  * nVertices);
       newBatches[i].offsetUVs         = newBatches[i].offsetNormals     + (sizeof(struct Coordinate)  * nVertices);
       newBatches[i].offsetBoneIndexes = newBatches[i].offsetUVs         + (sizeof(struct UVs)         * nVertices);
       newBatches[i].offsetBoneWeights = newBatches[i].offsetBoneIndexes + (sizeof(struct BoneIndexes) * nVertices);
       append(fn, (char*)(&newBatches[i]), sizeof(struct BatchData));
-      previousBatch                   = newBatches[i].offsetBoneWeights + (sizeof(struct BoneWeights) * nVertices);;
+      endOfPrevious                   = newBatches[i].offsetBoneWeights + (sizeof(struct BoneWeights) * nVertices);;
     }
 
     for (int i = 0; i < newmh.numBatch; i++) {