diff --git a/lib/Doctrine/ORM/Mapping/Driver/AnnotationDriver.php b/lib/Doctrine/ORM/Mapping/Driver/AnnotationDriver.php
index 59730f6b2..d916bafb3 100644
--- a/lib/Doctrine/ORM/Mapping/Driver/AnnotationDriver.php
+++ b/lib/Doctrine/ORM/Mapping/Driver/AnnotationDriver.php
@@ -472,7 +472,7 @@ class AnnotationDriver extends AbstractAnnotationDriver
 
                 // Check for `fetch`
                 if ($associationOverride->fetch) {
-                    $override['fetch'] = constant('Doctrine\ORM\Mapping\ClassMetadata::FETCH_' . $associationOverride->fetch);
+                    $override['fetch'] = constant(ClassMetadata::class . '::FETCH_' . $associationOverride->fetch);
                 }
 
                 $metadata->setAssociationOverride($fieldName, $override);
diff --git a/lib/Doctrine/ORM/Mapping/Driver/XmlDriver.php b/lib/Doctrine/ORM/Mapping/Driver/XmlDriver.php
index 0d51c4c92..2ca9190bc 100644
--- a/lib/Doctrine/ORM/Mapping/Driver/XmlDriver.php
+++ b/lib/Doctrine/ORM/Mapping/Driver/XmlDriver.php
@@ -623,7 +623,7 @@ class XmlDriver extends FileDriver
 
                 // Check for `fetch`
                 if (isset($overrideElement['fetch'])) {
-                    $override['fetch'] = constant('Doctrine\ORM\Mapping\ClassMetadata::FETCH_' . (string) $overrideElement['fetch']);
+                    $override['fetch'] = constant(ClassMetadata::class . '::FETCH_' . (string) $overrideElement['fetch']);
                 }
 
                 $metadata->setAssociationOverride($fieldName, $override);
diff --git a/lib/Doctrine/ORM/Mapping/Driver/YamlDriver.php b/lib/Doctrine/ORM/Mapping/Driver/YamlDriver.php
index 394722847..d65481be4 100644
--- a/lib/Doctrine/ORM/Mapping/Driver/YamlDriver.php
+++ b/lib/Doctrine/ORM/Mapping/Driver/YamlDriver.php
@@ -624,7 +624,7 @@ class YamlDriver extends FileDriver
 
                 // Check for `fetch`
                 if (isset($associationOverrideElement['fetch'])) {
-                    $override['fetch'] = constant('Doctrine\ORM\Mapping\ClassMetadata::FETCH_' . $associationOverrideElement['fetch']);
+                    $override['fetch'] = constant(ClassMetadata::class . '::FETCH_' . $associationOverrideElement['fetch']);
                 }
 
                 $metadata->setAssociationOverride($fieldName, $override);