diff --git a/source/Ox/js/Encoding.js b/source/Ox/js/Encoding.js
index 926b107e..a0ae93fc 100644
--- a/source/Ox/js/Encoding.js
+++ b/source/Ox/js/Encoding.js
@@ -223,7 +223,9 @@ Ox.decodeDeflate = function(string, callback) {
         try {
             // Parse the first byte as number of bytes to chop at the end,
             // and the rest, without these bytes, as an UTF8-encoded string.
-            string = Ox.decodeUTF8(string.slice(1, -string.charCodeAt(0)));
+            string = Ox.decodeUTF8(
+                string.slice(1, -string.charCodeAt(0) || void 0)
+            );
         } catch (e) {
             error();
         }