diff --git a/lib/matrix.js b/lib/matrix.js
index 34b2d97..0ce0e17 100644
--- a/lib/matrix.js
+++ b/lib/matrix.js
@@ -124,7 +124,7 @@ class Matrix {
   }
 
   static deserialize(data) {
-    if (typeof data == 'string') {
+    if (typeof data === 'string') {
       data = JSON.parse(data);
     }
     let matrix = new Matrix(data.rows, data.cols);