diff --git a/test/built-ins/Promise/prototype/finally/this-value-non-object.js b/test/built-ins/Promise/prototype/finally/this-value-non-object.js
index 1e8467b9b8..d88a70a0be 100644
--- a/test/built-ins/Promise/prototype/finally/this-value-non-object.js
+++ b/test/built-ins/Promise/prototype/finally/this-value-non-object.js
@@ -8,6 +8,8 @@ esid: sec-promise.prototype.finally
 features: [Promise.prototype.finally]
 ---*/
 
+assert.sameValue(typeof Promise.prototype.finally, 'function');
+
 assert.throws(TypeError, function() {
   Promise.prototype.finally.call(undefined);
 }, 'undefined');
diff --git a/test/built-ins/Promise/prototype/finally/this-value-then-not-callable.js b/test/built-ins/Promise/prototype/finally/this-value-then-not-callable.js
index 253e22fe38..5ba20e2253 100644
--- a/test/built-ins/Promise/prototype/finally/this-value-then-not-callable.js
+++ b/test/built-ins/Promise/prototype/finally/this-value-then-not-callable.js
@@ -8,6 +8,7 @@ description: >
 esid: sec-promise.prototype.finally
 features: [Symbol, Promise.prototype.finally]
 ---*/
+assert.sameValue(typeof Promise.prototype.finally, 'function');
 
 var symbol = Symbol();