diff --git a/test/built-ins/RegExp/duplicate-flags.js b/test/built-ins/RegExp/duplicate-flags.js
index d689acc937..0339f83f26 100644
--- a/test/built-ins/RegExp/duplicate-flags.js
+++ b/test/built-ins/RegExp/duplicate-flags.js
@@ -10,9 +10,20 @@ description: Check that duplicate RegExp flags are disallowed
 features: [regexp-dotall]
 ---*/
 
+new RegExp("", "mig"); // single g will not throw SyntaxError
 assert.throws(SyntaxError, () => new RegExp("", "migg"), "duplicate g");
+
+new RegExp("", "i"); // single i will not throw SyntaxError
 assert.throws(SyntaxError, () => new RegExp("", "ii"), "duplicate i");
+
+new RegExp("", "m"); // single m will not throw SyntaxError
 assert.throws(SyntaxError, () => new RegExp("", "mm"), "duplicate m");
+
+new RegExp("", "s"); // single s will not throw SyntaxError
 assert.throws(SyntaxError, () => new RegExp("", "ss"), "duplicate s");
+
+new RegExp("", "u"); // single u will not throw SyntaxError
 assert.throws(SyntaxError, () => new RegExp("", "uu"), "duplicate u");
+
+new RegExp("", "y"); // single y will not throw SyntaxError
 assert.throws(SyntaxError, () => new RegExp("", "yy"), "duplicate y");
diff --git a/test/built-ins/String/prototype/matchAll/regexp-matchAll-not-callable.js b/test/built-ins/String/prototype/matchAll/regexp-matchAll-not-callable.js
index de3568c346..ef66ce9d8b 100644
--- a/test/built-ins/String/prototype/matchAll/regexp-matchAll-not-callable.js
+++ b/test/built-ins/String/prototype/matchAll/regexp-matchAll-not-callable.js
@@ -11,6 +11,8 @@ info: |
 features: [Symbol.matchAll, String.prototype.matchAll]
 ---*/
 
+assert.sameValue(typeof String.prototype.matchAll, "function");
+
 var regexp = /./;
 
 regexp[Symbol.matchAll] = true;
diff --git a/test/built-ins/String/prototype/matchAll/regexp-prototype-has-no-matchAll.js b/test/built-ins/String/prototype/matchAll/regexp-prototype-has-no-matchAll.js
index ee2b9484ce..d7c2b2f575 100644
--- a/test/built-ins/String/prototype/matchAll/regexp-prototype-has-no-matchAll.js
+++ b/test/built-ins/String/prototype/matchAll/regexp-prototype-has-no-matchAll.js
@@ -18,6 +18,8 @@ features: [Symbol.matchAll, String.prototype.matchAll]
 includes: [compareArray.js, compareIterator.js, regExpUtils.js]
 ---*/
 
+assert.sameValue(typeof String.prototype.matchAll, "function");
+
 delete RegExp.prototype[Symbol.matchAll];
 var str = '/a/g*/b/g';
 
diff --git a/test/intl402/Segmenter/constructor/constructor/options-invalid.js b/test/intl402/Segmenter/constructor/constructor/options-invalid.js
index 62c9b6dc29..4273fdee5d 100644
--- a/test/intl402/Segmenter/constructor/constructor/options-invalid.js
+++ b/test/intl402/Segmenter/constructor/constructor/options-invalid.js
@@ -12,4 +12,6 @@ info: |
 features: [Intl.Segmenter]
 ---*/
 
+assert.sameValue(typeof Intl.Segmenter, "function");
+
 assert.throws(TypeError, function() { new Intl.Segmenter([], null) })