diff --git a/MessageCatalogue.php b/MessageCatalogue.php
index a5a57be6..ff49b5a9 100644
--- a/MessageCatalogue.php
+++ b/MessageCatalogue.php
@@ -49,11 +49,10 @@ public function getLocale()
     public function getDomains()
     {
         $domains = [];
-        $suffixLength = \strlen(self::INTL_DOMAIN_SUFFIX);
 
         foreach ($this->messages as $domain => $messages) {
-            if (\strlen($domain) > $suffixLength && false !== $i = strpos($domain, self::INTL_DOMAIN_SUFFIX, -$suffixLength)) {
-                $domain = substr($domain, 0, $i);
+            if (str_ends_with($domain, self::INTL_DOMAIN_SUFFIX)) {
+                $domain = substr($domain, 0, -\strlen(self::INTL_DOMAIN_SUFFIX));
             }
             $domains[$domain] = $domain;
         }
@@ -68,7 +67,7 @@ public function all(string $domain = null)
     {
         if (null !== $domain) {
             // skip messages merge if intl-icu requested explicitly
-            if (str_contains($domain, self::INTL_DOMAIN_SUFFIX)) {
+            if (str_ends_with($domain, self::INTL_DOMAIN_SUFFIX)) {
                 return $this->messages[$domain] ?? [];
             }
 
@@ -76,11 +75,10 @@ public function all(string $domain = null)
         }
 
         $allMessages = [];
-        $suffixLength = \strlen(self::INTL_DOMAIN_SUFFIX);
 
         foreach ($this->messages as $domain => $messages) {
-            if (\strlen($domain) > $suffixLength && false !== $i = strpos($domain, self::INTL_DOMAIN_SUFFIX, -$suffixLength)) {
-                $domain = substr($domain, 0, $i);
+            if (str_ends_with($domain, self::INTL_DOMAIN_SUFFIX)) {
+                $domain = substr($domain, 0, -\strlen(self::INTL_DOMAIN_SUFFIX));
                 $allMessages[$domain] = $messages + ($allMessages[$domain] ?? []);
             } else {
                 $allMessages[$domain] = ($allMessages[$domain] ?? []) + $messages;
@@ -161,8 +159,7 @@ public function add(array $messages, string $domain = 'messages')
             $this->messages[$domain] = [];
         }
         $intlDomain = $domain;
-        $suffixLength = \strlen(self::INTL_DOMAIN_SUFFIX);
-        if (\strlen($domain) < $suffixLength || !str_contains($domain, self::INTL_DOMAIN_SUFFIX, -$suffixLength)) {
+        if (!str_ends_with($domain, self::INTL_DOMAIN_SUFFIX)) {
             $intlDomain .= self::INTL_DOMAIN_SUFFIX;
         }
         foreach ($messages as $id => $message) {
diff --git a/Tests/TranslatorCacheTest.php b/Tests/TranslatorCacheTest.php
index 2d890c8c..3720aeb7 100644
--- a/Tests/TranslatorCacheTest.php
+++ b/Tests/TranslatorCacheTest.php
@@ -104,7 +104,7 @@ public function testCatalogueIsReloadedWhenResourcesAreNoLongerFresh()
         $catalogue = new MessageCatalogue($locale, []);
         $catalogue->addResource(new StaleResource()); // better use a helper class than a mock, because it gets serialized in the cache and re-loaded
 
-        /** @var LoaderInterface|MockObject $loader */
+        /** @var MockObject&LoaderInterface $loader */
         $loader = $this->createMock(LoaderInterface::class);
         $loader
             ->expects($this->exactly(2))