diff --git a/.travis.yml b/.travis.yml
index 64c48eb..08cbf00 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,10 +10,10 @@ install:
 - wget https://dl.google.com/closure-compiler/compiler-latest.zip -O closure-compiler.zip
 - unzip closure-compiler.zip -d closure-compiler
 script:
-- printf "// $VERSION - $GH_SCRIPT_URL\n$(cat script.js)" > script.js
+- printf "// $VERSION - $GH_SCRIPT_URL\n$(cat script.js)\n" > script.js
 - cat script.js
 - 'curl -X POST -s --data-urlencode "input@script.js" https://javascript-minifier.com/raw > minified.js'
-- printf "$(head -n 1 script.js)\n$(cat minified.js)" > minified.js
+- printf "$(head -n 1 script.js)\n$(cat minified.js)\n" > minified.js
 - cat minified.js
 - npm test
 before_deploy:
@@ -37,4 +37,4 @@ deploy:
     condition: $(git describe --tags --abbrev=0) != $VERSION
 cache:
   directories:
-  - node_modules
\ No newline at end of file
+  - node_modules
diff --git a/package.json b/package.json
index a28441e..40c3d6f 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "anki-persistence",
-  "version": "0.5.2",
+  "version": "0.5.3",
   "description": "Persist data between both sides of an anki flashcard.",
   "main": "script.js",
   "directories": {
diff --git a/script.js b/script.js
index 6f7d887..b00ccd8 100644
--- a/script.js
+++ b/script.js
@@ -59,7 +59,7 @@ if (typeof(window.Persistence) === 'undefined') {
         if (key == undefined) {
           key = _defaultKey;
         }
-        return obj[_persistenceKey][key] || null;
+        return obj[_persistenceKey][key] == undefined ? null : obj[_persistenceKey][key];
       };
       this.removeItem = function(key) {
         if (key == undefined) {
@@ -99,4 +99,4 @@ if (typeof(window.Persistence) === 'undefined') {
       window.Persistence = new Persistence_windowKey("qt"); // linux, mac (2.1)
     }
   }
-}
\ No newline at end of file
+}