diff --git a/test/intl402/PluralRules/internals.js b/test/intl402/PluralRules/internals.js
index 1de97b3cdf..104428dfda 100644
--- a/test/intl402/PluralRules/internals.js
+++ b/test/intl402/PluralRules/internals.js
@@ -12,10 +12,6 @@ author: Zibi Braniecki
 var obj = new Intl.PluralRules();
 
 var actualPrototype = Object.getPrototypeOf(obj);
-if (actualPrototype !== Intl.PluralRules.prototype) {
-    $ERROR("Prototype of object constructed by Intl.PluralRules isn't Intl.PluralRules.prototype; got " + actualPrototype);
-}
+assert.sameValue(actualPrototype, Intl.PluralRules.prototype, "Prototype of object constructed by Intl.PluralRules isn't Intl.PluralRules.prototype; got " + actualPrototype);
 
-if (!Object.isExtensible(obj)) {
-    $ERROR("Object constructed by Intl.PluralRules must be extensible.");
-}
+assert(Object.isExtensible(obj), "Object constructed by Intl.PluralRules must be extensible.");
diff --git a/test/intl402/PluralRules/prototype/bind.js b/test/intl402/PluralRules/prototype/bind.js
index fb07bd6e9f..7da84c681f 100644
--- a/test/intl402/PluralRules/prototype/bind.js
+++ b/test/intl402/PluralRules/prototype/bind.js
@@ -19,16 +19,8 @@ var invalidTargets = [undefined, null, true, 0, "PluralRules", [], {}];
 Object.getOwnPropertyNames(functions).forEach(function (functionName) {
     var f = functions[functionName];
     invalidTargets.forEach(function (target) {
-        var error;
-        try {
+        assert.throws(TypeError, function () {
             f.call(target);
-        } catch (e) {
-            error = e;
-        }
-        if (error === undefined) {
-            $ERROR("Calling " + functionName + " on " + target + " was not rejected.");
-        } else if (error.name !== "TypeError") {
-            $ERROR("Calling " + functionName + " on " + target + " was rejected with wrong error " + error.name + ".");
-        }
+        }, "Calling " + functionName + " on " + target + " was not rejected.");
     });
 });
diff --git a/test/intl402/PluralRules/prototype/constructor/main.js b/test/intl402/PluralRules/prototype/constructor/main.js
index b76316ebd9..fb8634d019 100644
--- a/test/intl402/PluralRules/prototype/constructor/main.js
+++ b/test/intl402/PluralRules/prototype/constructor/main.js
@@ -9,7 +9,4 @@ description: >
 author: Zibi Braniecki
 ---*/
 
-if (Intl.PluralRules.prototype.constructor !== Intl.PluralRules) {
-    $ERROR("Intl.PluralRules.prototype.constructor is not the same as " +
-          "Intl.PluralRules");
-}
+assert.sameValue(Intl.PluralRules.prototype.constructor, Intl.PluralRules, "Intl.PluralRules.prototype.constructor is not the same as Intl.PluralRules");
diff --git a/test/intl402/PluralRules/prototype/properties.js b/test/intl402/PluralRules/prototype/properties.js
index 7c05f838ee..56faeca8a3 100644
--- a/test/intl402/PluralRules/prototype/properties.js
+++ b/test/intl402/PluralRules/prototype/properties.js
@@ -8,15 +8,7 @@ author: Zibi Braniecki
 ---*/
 
 var desc = Object.getOwnPropertyDescriptor(Intl.PluralRules, "prototype");
-if (desc === undefined) {
-    $ERROR("Intl.PluralRules.prototype is not defined.");
-}
-if (desc.writable) {
-    $ERROR("Intl.PluralRules.prototype must not be writable.");
-}
-if (desc.enumerable) {
-    $ERROR("Intl.PluralRules.prototype must not be enumerable.");
-}
-if (desc.configurable) {
-    $ERROR("Intl.PluralRules.prototype must not be configurable.");
-}
+assert.notSameValue(desc, undefined, "Intl.PluralRules.prototype is not defined.");
+assert.sameValue(desc.writable, false, "Intl.PluralRules.prototype must not be writable.");
+assert.sameValue(desc.enumerable, false, "Intl.PluralRules.prototype must not be enumerable.");
+assert.sameValue(desc.configurable, false, "Intl.PluralRules.prototype must not be configurable.");
diff --git a/test/intl402/PluralRules/prototype/resolvedOptions/properties.js b/test/intl402/PluralRules/prototype/resolvedOptions/properties.js
index 05f7ea37a3..355a5ab8c0 100644
--- a/test/intl402/PluralRules/prototype/resolvedOptions/properties.js
+++ b/test/intl402/PluralRules/prototype/resolvedOptions/properties.js
@@ -14,9 +14,7 @@ includes: [testIntl.js]
 var actual = new Intl.PluralRules().resolvedOptions();
 
 var actual2 = new Intl.PluralRules().resolvedOptions();
-if (actual2 === actual) {
-    $ERROR("resolvedOptions returned the same object twice.");
-}
+assert.notSameValue(actual2, actual, "resolvedOptions returned the same object twice.");
 
 // this assumes the default values where the specification provides them
 mustHaveProperty(actual, "locale", isCanonicalizedStructurallyValidLanguageTag);
diff --git a/test/intl402/PluralRules/supportedLocalesOf/main.js b/test/intl402/PluralRules/supportedLocalesOf/main.js
index f9888165c2..f7661aa31b 100644
--- a/test/intl402/PluralRules/supportedLocalesOf/main.js
+++ b/test/intl402/PluralRules/supportedLocalesOf/main.js
@@ -15,15 +15,9 @@ var requestedLocales = [defaultLocale, notSupported];
     
 var supportedLocales;
 
-if (!Intl.PluralRules.hasOwnProperty('supportedLocalesOf')) {
-    $ERROR("Intl.PluralRules doesn't have a supportedLocalesOf property.");
-}
+assert(Intl.PluralRules.hasOwnProperty('supportedLocalesOf'), "Intl.PluralRules doesn't have a supportedLocalesOf property.");
     
 supportedLocales = Intl.PluralRules.supportedLocalesOf(requestedLocales);
-if (supportedLocales.length !== 1) {
-    $ERROR('The length of supported locales list is not 1.');
-}
-    
-if (supportedLocales[0] !== defaultLocale) {
-    $ERROR('The default locale is not returned in the supported list.');
-}
+assert.sameValue(supportedLocales.length, 1, 'The length of supported locales list is not 1.');
+
+assert.sameValue(supportedLocales[0], defaultLocale, 'The default locale is not returned in the supported list.');