diff --git a/lib/Matrix2D.js b/lib/Matrix2D.js
index 1fba91c0..ae634e53 100644
--- a/lib/Matrix2D.js
+++ b/lib/Matrix2D.js
@@ -83,7 +83,7 @@ export default class Matrix2D {
         this.a = a == null ? 1 : a;
         this.b = b || 0;
         this.c = c || 0;
-        this.d = b == null ? 1 : d;
+        this.d = d == null ? 1 : d;
         this.tx = tx || 0;
         this.ty = ty || 0;
         return this;