diff --git a/challenges/02-javascript-algorithms-and-data-structures/object-oriented-programming.json b/challenges/02-javascript-algorithms-and-data-structures/object-oriented-programming.json
index 1b48605dce..0e76ff0e81 100644
--- a/challenges/02-javascript-algorithms-and-data-structures/object-oriented-programming.json
+++ b/challenges/02-javascript-algorithms-and-data-structures/object-oriented-programming.json
@@ -446,7 +446,7 @@
"A more efficient way is to set the prototype to a new object that already contains the properties. This way, the properties are added all at once:",
"Bird.prototype = {
numLegs: 2,
eat: function() {
console.log(\"nom nom nom\");
},
describe: function() {
console.log(\"My name is \" + this.name);
}
};
",
"
",
- "Add three properties numLegs, eat, and describe to the prototype of Dog by setting the prototype to a new object. The properties can be set to any values."
+ "Add the property numLegs and the two methods eat() and describe() to the prototype of Dog by setting the prototype to a new object."
],
"challengeSeed": [
"function Dog(name) {",
@@ -461,8 +461,8 @@
"tests": [
"assert((/Dog\\.prototype\\s*?=\\s*?{/).test(code), 'message: Dog.prototype should be set to a new object.');",
"assert(Dog.prototype.numLegs !== undefined, 'message: Dog.prototype should have the property numLegs.');",
- "assert(Dog.prototype.eat !== undefined, 'message: Dog.prototype should have the property eat.'); ",
- "assert(Dog.prototype.describe !== undefined, 'message: Dog.prototype should have the property describe.'); "
+ "assert(typeof Dog.prototype.eat === 'function', 'message: Dog.prototype should have the method eat().'); ",
+ "assert(typeof Dog.prototype.describe === 'function', 'message: Dog.prototype should have the method describe().'); "
],
"solutions": [],
"hints": [],