diff --git a/.gitignore b/.gitignore
index daf97ad3..939186ff 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,4 @@
 coverage/
 .nyc_output/
 node_modules/
-npm-debug.log
\ No newline at end of file
+npm-debug.log
diff --git a/index.js b/index.js
index 5cdc8661..61581545 100644
--- a/index.js
+++ b/index.js
@@ -9,12 +9,13 @@ var noop = require('noop3');
 function is(x) {
     // this line calls the noop function
     noop();
-
+    
+    // Every element should be lower case
     var thirteenStrings = [
-        '1101', // Binary 13
+        1101, // Binary 13
         "xiii", // Roman numeral 13
-        "0xD", // Hex 13
-
+        "0xd", // Hex 13
+        
         "https://scontent.cdninstagram.com/hphotos-xtf1/t51.2885-15/s320x320/e35/12237511_444845689040315_1101385461_n.jpg", // Just because we can
         "https://www.youtube.com/watch?v=pte3Jg-2Ax4", // Thirteen by Big Star
         "https://www.youtube.com/watch?v=33Kv5D2zwyc", // The best Johny Cash's song
@@ -67,8 +68,8 @@ function is(x) {
         "dreizehn", // German
         "drizäh", // Swiss German
         "wa’maH wej" // Klingon
-      "שלוש עשרה", // Hebrew
-      "तेरह", //Hindi
+		"שלוש עשרה", // Hebrew
+		"तेरह", //Hindi
         "tizenhárom", // Hungarian
         "trí déag", // Irish
         "tredici", // Italian
@@ -121,6 +122,12 @@ function is(x) {
         },
         roughly: {
             thirteen: function() {
+                for (var i = 0, len = thirteenStrings.length; i < len; i++) {
+                    if (('' + x).toLowerCase().indexOf(('' + thirteenStrings[i])) > -1) {
+                        return true;
+                    }
+                }
+                
                 return x >= 12.5 && x < 13.5;
             }
         },