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 1e8467b9b86b2d9a72c8e4c0f919f783ca3b37f9..d88a70a0be557c7b11671d9269ebceb7479ef488 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 253e22fe38c39fa01a54234996c09ffa057240e7..5ba20e22532a16e41c97a81cc7471e646c960fba 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();