diff --git a/.github/workflows/coding-standards.yml b/.github/workflows/coding-standards.yml
index c99f74c1..7bd76d27 100644
--- a/.github/workflows/coding-standards.yml
+++ b/.github/workflows/coding-standards.yml
@@ -12,4 +12,4 @@ on:
 jobs:
   coding-standards:
     name: "Coding Standards"
-    uses: "doctrine/.github/.github/workflows/coding-standards.yml@15.0.0"
+    uses: "doctrine/.github/.github/workflows/coding-standards.yml@15.1.0"
diff --git a/.github/workflows/continuous-integration.yml b/.github/workflows/continuous-integration.yml
index f96e78c8..6ffae26e 100644
--- a/.github/workflows/continuous-integration.yml
+++ b/.github/workflows/continuous-integration.yml
@@ -12,7 +12,7 @@ on:
 jobs:
   phpunit:
     name: "PHPUnit"
-    uses: "doctrine/.github/.github/workflows/continuous-integration.yml@15.0.0"
+    uses: "doctrine/.github/.github/workflows/continuous-integration.yml@15.1.0"
     with:
       php-versions: '["8.1", "8.2", "8.3", "8.4", "8.5"]'
       phpunit-options-lowest: "--do-not-fail-on-deprecation"
diff --git a/.github/workflows/documentation.yml b/.github/workflows/documentation.yml
index 640f06bd..04037de7 100644
--- a/.github/workflows/documentation.yml
+++ b/.github/workflows/documentation.yml
@@ -17,4 +17,4 @@ on:
 jobs:
   documentation:
     name: "Documentation"
-    uses: "doctrine/.github/.github/workflows/documentation.yml@15.0.0"
+    uses: "doctrine/.github/.github/workflows/documentation.yml@15.1.0"
diff --git a/.github/workflows/release-on-milestone-closed.yml b/.github/workflows/release-on-milestone-closed.yml
index 7100986c..786e150b 100644
--- a/.github/workflows/release-on-milestone-closed.yml
+++ b/.github/workflows/release-on-milestone-closed.yml
@@ -8,7 +8,7 @@ on:
 jobs:
   release:
     name: "Git tag, release & create merge-up PR"
-    uses: "doctrine/.github/.github/workflows/release-on-milestone-closed.yml@15.0.0"
+    uses: "doctrine/.github/.github/workflows/release-on-milestone-closed.yml@15.1.0"
     secrets:
       GIT_AUTHOR_EMAIL: ${{ secrets.GIT_AUTHOR_EMAIL }}
       GIT_AUTHOR_NAME: ${{ secrets.GIT_AUTHOR_NAME }}
diff --git a/.github/workflows/static-analysis.yml b/.github/workflows/static-analysis.yml
index 3d078651..dc26e323 100644
--- a/.github/workflows/static-analysis.yml
+++ b/.github/workflows/static-analysis.yml
@@ -12,4 +12,4 @@ on:
 jobs:
   static-analysis:
     name: "Static Analysis"
-    uses: "doctrine/.github/.github/workflows/phpstan.yml@15.0.0"
+    uses: "doctrine/.github/.github/workflows/phpstan.yml@15.1.0"
diff --git a/src/ManagerRegistry.php b/src/ManagerRegistry.php
index 2e0a389c..43ac855d 100644
--- a/src/ManagerRegistry.php
+++ b/src/ManagerRegistry.php
@@ -5,7 +5,7 @@
 namespace Doctrine\Persistence;
 
 /**
- * Contract covering object managers for a Doctrine persistence layer ManagerRegistry class to implement.
+ * Gives access to the object managers and connections of an application, by name or by class.
  */
 interface ManagerRegistry extends ConnectionRegistry
 {
diff --git a/src/Mapping/Driver/SymfonyFileLocator.php b/src/Mapping/Driver/SymfonyFileLocator.php
index 09339fae..5d9b1ceb 100644
--- a/src/Mapping/Driver/SymfonyFileLocator.php
+++ b/src/Mapping/Driver/SymfonyFileLocator.php
@@ -11,16 +11,14 @@
 use RuntimeException;
 
 use function array_keys;
-use function assert;
+use function basename;
 use function is_dir;
 use function is_file;
-use function is_int;
 use function realpath;
 use function sprintf;
 use function str_replace;
 use function str_starts_with;
 use function strlen;
-use function strrpos;
 use function strtr;
 use function substr;
 
@@ -222,12 +220,9 @@ public function findMappingFile(string $className): string
             }
         }
 
-        $pos = strrpos($className, '\\');
-        assert(is_int($pos));
-
         throw MappingException::mappingFileNotFound(
             $className,
-            substr($className, $pos + 1) . $this->fileExtension,
+            basename(str_replace('\\', '/', $className)) . $this->fileExtension,
         );
     }
 
diff --git a/tests/Mapping/SymfonyFileLocatorTest.php b/tests/Mapping/SymfonyFileLocatorTest.php
index ff7767d8..0b58d5b4 100644
--- a/tests/Mapping/SymfonyFileLocatorTest.php
+++ b/tests/Mapping/SymfonyFileLocatorTest.php
@@ -188,6 +188,15 @@ public function testFindMappingFileNotFound(): void
         $locator->findMappingFile('Foo\\stdClass2');
     }
 
+    public function testFindMappingFileNotFoundForClassInRootNamespace(): void
+    {
+        $locator = new SymfonyFileLocator([], '.yml');
+
+        $this->expectException(MappingException::class);
+        $this->expectExceptionMessage("No mapping file found named 'DateTime.yml' for class 'DateTime'.");
+        $locator->findMappingFile('DateTime');
+    }
+
     public function testFindMappingFileLeastSpecificNamespaceFirst(): void
     {
         // Low -> High