diff --git a/src/core/image.js b/src/core/image.js
index 466b49833..7e01fb528 100644
--- a/src/core/image.js
+++ b/src/core/image.js
@@ -253,7 +253,7 @@ var PDFImage = (function PDFImageClosure() {
     // in this thread can be relying on its contents.
     if (inverseDecode) {
       for (i = 0; i < actualLength; i++) {
-        data[i] = ~data[i];
+        data[i] ^= 0xFF;
       }
     }