diff --git a/src/Symfony/Component/Translation/Tests/TranslatorTest.php b/src/Symfony/Component/Translation/Tests/TranslatorTest.php
index 68122b2915..f0d87773ba 100644
--- a/src/Symfony/Component/Translation/Tests/TranslatorTest.php
+++ b/src/Symfony/Component/Translation/Tests/TranslatorTest.php
@@ -12,6 +12,7 @@
 namespace Symfony\Component\Translation\Tests;
 
 use PHPUnit\Framework\TestCase;
+use Symfony\Component\Translation\Exception\RuntimeException;
 use Symfony\Component\Translation\Loader\ArrayLoader;
 use Symfony\Component\Translation\MessageCatalogue;
 use Symfony\Component\Translation\Translator;
@@ -552,6 +553,16 @@ class TranslatorTest extends TestCase
         // unchanged if it can't be found
         $this->assertEquals('some_message2', $translator->transChoice('some_message2', 10, ['%count%' => 10]));
     }
+
+    public function testMissingLoaderForResourceError()
+    {
+        $this->expectException(RuntimeException::class);
+        $this->expectExceptionMessage('No loader is registered for the "twig" format when loading the "messages.en.twig" resource.');
+
+        $translator = new Translator('en');
+        $translator->addResource('twig', 'messages.en.twig', 'en');
+        $translator->getCatalogue('en');
+    }
 }
 
 class StringClass
diff --git a/src/Symfony/Component/Translation/Translator.php b/src/Symfony/Component/Translation/Translator.php
index 1bda62d1b1..131459c6e3 100644
--- a/src/Symfony/Component/Translation/Translator.php
+++ b/src/Symfony/Component/Translation/Translator.php
@@ -376,7 +376,11 @@ EOF
         if (isset($this->resources[$locale])) {
             foreach ($this->resources[$locale] as $resource) {
                 if (!isset($this->loaders[$resource[0]])) {
-                    throw new RuntimeException(sprintf('The "%s" translation loader is not registered.', $resource[0]));
+                    if (\is_string($resource[1])) {
+                        throw new RuntimeException(sprintf('No loader is registered for the "%s" format when loading the "%s" resource.', $resource[0], $resource[1]));
+                    }
+
+                    throw new RuntimeException(sprintf('No loader is registered for the "%s" format.', $resource[0]));
                 }
                 $this->catalogues[$locale]->addCatalogue($this->loaders[$resource[0]]->load($resource[1], $locale, $resource[2]));
             }