diff --git a/poincare/include/poincare/product.h b/poincare/include/poincare/product.h
index 292803e31..71d95b723 100644
--- a/poincare/include/poincare/product.h
+++ b/poincare/include/poincare/product.h
@@ -34,11 +34,11 @@ friend class ProductNode;
 public:
   Product();
   Product(const ProductNode * n) : Expression(n) {}
-  Product(Expression operand0, Expression operand1, Expression operand2, Expression op) : Product() {
+  Product(Expression operand0, Expression operand1, Expression operand2, Expression operand3) : Product() {
     replaceChildAtIndexInPlace(0, operand0);
     replaceChildAtIndexInPlace(1, operand1);
     replaceChildAtIndexInPlace(2, operand2);
-    replaceChildAtIndexInPlace(3, operand2);
+    replaceChildAtIndexInPlace(3, operand3);
   }
 };