diff --git a/is.js b/is.js
index 42f641be..45fd364f 100644
--- a/is.js
+++ b/is.js
@@ -116,7 +116,13 @@ var is = function is(x) {
         },
         canSpell: {
           thirteen: function(){
-            return x.toLowerCase().includes("t","h","i","r","t","e","e","n");
+            if (x === 13) { return true; }
+            for (let [key, value] of Object.entries({"t": 2, "h": 1, "i": 1, "r": 1, "e": 2, "n": 1})) {
+              if ((x.match(new RegExp(key, "g")) || []).length < value) {
+                return false;
+              }
+            }
+            return true;
           }
         },
         anagramOf:{
diff --git a/test.js b/test.js
index 9aa834a7..f5d8dba8 100644
--- a/test.js
+++ b/test.js
@@ -184,6 +184,11 @@ tap.equal(is(10).minus(1).plus(32).dividedby(4).times(3).thirteen(), false) // (
 
 tap.equal(is(5.3).plus(0.5).times(5).minus(4).dividedby(2).roughly.thirteen(), true) // (((12.5 * 2) + 4) / 5) - .5
 
+tap.equal(is("thirtee").canSpell.thirteen(), false);
+tap.equal(is("truck").canSpell.thirteen(), false);
+tap.equal(is("thirteen").canSpell.thirteen(), true);
+tap.equal(is("thirsty and a teen").canSpell.thirteen(), true);
+
 tap.equal(is(13).base(10).thirteen(), true);
 tap.equal(is(14).base(10).thirteen(), false);
 tap.equal(is("1101").base(2).thirteen(), true);