diff --git a/src/files/bm.js b/src/files/bm.js
index 514c222..a0bf43d 100644
--- a/src/files/bm.js
+++ b/src/files/bm.js
@@ -127,7 +127,7 @@ export function parse(dataView, start, size) { // eslint-disable-line
   if (compression) {
     const offsets = []
     for (let index = 0; index < width; index++) {
-      const offset = dataView.getUint32(32 + (index * 4), true)
+      const offset = dataView.getUint32(start + 32 + (index * 4), true)
       offsets.push(start + offset)
     }
     console.log('BM Compressed')