diff --git a/third_party/zxing-js.umd.js b/third_party/zxing-js.umd.js
index 6cb3d6f4..8dcf5431 100644
--- a/third_party/zxing-js.umd.js
+++ b/third_party/zxing-js.umd.js
@@ -13713,7 +13713,7 @@
             if (this.parsedFormatInfo === null) {
                 return; // We have no format information, and have no data mask
             }
-            const dataMask = DataMask.values[this.parsedFormatInfo.getDataMask()];
+            const dataMask = DataMask.values.get(this.parsedFormatInfo.getDataMask());
             const dimension = this.bitMatrix.getHeight();
             dataMask.unmaskBitMatrix(this.bitMatrix, dimension);
         }