diff --git a/CHANGELOG b/CHANGELOG
index 03e508d..11b3d44 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,6 @@
+January 2018
+  1.4.2 checking entered terminal and PIN key values to be [^a-fA-F0-9]
+
 December 2017
   1.4.1 clearButtonClasses() and clearIconClasses() refactored
   1.4.0 Removed duplicated code from src/listeners/settings.js
diff --git a/package.json b/package.json
index 766362e..b87cace 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "electron-atm",
   "productName": "Electron ATM",
-  "version": "1.4.1",
+  "version": "1.4.2",
   "description": "A simple APTRA Advance NDC ATM emulator",
   "main": "main.js",
   "scripts": {
diff --git a/src/listeners/settings.js b/src/listeners/settings.js
index f5a78ed..356ca77 100644
--- a/src/listeners/settings.js
+++ b/src/listeners/settings.js
@@ -20,10 +20,12 @@ $(function(){
     setInterval(function(){
      if(keys[type] !== $('#settings-' + type + '-key').val()){
        keys[type] = $('#settings-' + type + '-key').val();
-  
+
+       keys[type] = keys[type].replace(/[^a-fA-F0-9]/g,'');
+       $('#settings-' + type + '-key').val(keys[type].toUpperCase());
+
        if(keys[type].length === 32){
          $('#settings-' + type + '-key-cv').val(crypto.getKeyCheckValue(keys[type]));
-         $('#settings-' + type + '-key').val(keys[type].toUpperCase());
        } else {
          $('#settings-' + type + '-key-cv').val('');
        }