diff --git a/package.json b/package.json
index 9ace955..790f8f5 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "boolerjs",
-  "version": "0.0.1",
+  "version": "0.0.2",
   "description": "Convert string to Boolean in JavaScript.",
   "main": "index.js",
   "scripts": {
diff --git a/src/booler.js b/src/booler.js
index 523aebd..d469a32 100644
--- a/src/booler.js
+++ b/src/booler.js
@@ -7,7 +7,7 @@
  */
 const booler = (val) => {
     // transform to string lower case.
-    val = val + "".toLowerCase();
+    val = (val + "").toLowerCase();
     return val == 't' || val == 'true' || val == 1;
 }
 
diff --git a/test/booler.test.js b/test/booler.test.js
index de5540d..adadd7c 100644
--- a/test/booler.test.js
+++ b/test/booler.test.js
@@ -5,6 +5,10 @@ it('booler will be pass it to equal true', () => {
     assert.equal(true, booler(true));
 })
 
+it('booler will be pass it to equal True', () => {
+    assert.equal(true, booler('True'));
+})
+
 it(`booler will be pass it to equal 'true'`, () => {
     assert.equal(true, booler('true'));
 })