@@ -1411,7 +1411,7 @@ classes until you find yourself needing larger and more complex objects.
 ```javascript
 const Animal = function(age) {
 if (!(this instanceof Animal)) {
-throw new Error("Instantiate Animal with `new`");
+throw new Error('Instantiate Animal with `new`');
 }
 
 this.age = age;
@@ -1421,7 +1421,7 @@ Animal..move = function() {};
 
 const Mammal = function(age, furColor) {
 if (!(this instanceof Mammal)) {
-throw new Error("Instantiate Mammal with `new`");
+throw new Error('Instantiate Mammal with `new`');
 }
 
 Animal.call(this, age);
@@ -1434,7 +1434,7 @@ Mammal..liveBirth = function() {};
 
 const Human = function(age, furColor, languageSpoken) {
 if (!(this instanceof Human)) {
-throw new Error("Instantiate Human with `new`");
+throw new Error('Instantiate Human with `new`');
 }
 
 Mammal.call(this, age, furColor);