diff --git a/src/js/ConfigInserter.js b/src/js/ConfigInserter.js
index fd7d0d6a..d6431347 100644
--- a/src/js/ConfigInserter.js
+++ b/src/js/ConfigInserter.js
@@ -60,6 +60,9 @@ function generateData(firmware, input, startAddress) {
         throw new Error('Configuration area in firmware not free.');
     }
 
+    // Add 0 terminator
+    input = input + '\0';
+
     var inputIndex = 0;
     while (inputIndex < input.length) {
         var remaining = input.length - inputIndex;