diff --git a/app.js b/app.js
index 0d03661..c326d0b 100644
--- a/app.js
+++ b/app.js
@@ -58,6 +58,7 @@ var App = new Vue({
* @return {[string]} [roman numeral conversion of provided whole number]
*/
function intToRoman(n) {
+ if (n <= 0 || n >= 5000) return '';
// Set up mapping to compare crucial roman numerals to their integet values
var mapping = {
'M': 1000, 'CM': 900, 'D': 500, 'CD': 400, 'C': 100,
diff --git a/index.html b/index.html
index f76bfbd..06d7203 100644
--- a/index.html
+++ b/index.html
@@ -34,7 +34,7 @@
Roman Numerals