diff --git a/UPGRADE.md b/UPGRADE.md
index 8fb7172b20a..decf8f4fa85 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -8,6 +8,11 @@ awareness about deprecated code.
 
 # Upgrade to 4.0
 
+## BC BREAK: Removed lock-related `AbstractPlatform` methods
+
+The methods `AbstractPlatform::getReadLockSQL()`, `::getWriteLockSQL()` and `::getForUpdateSQL()` have been removed
+Use `QueryBuilder::forUpdate()` as a replacement for the latter.
+
 ## BC BREAK: BIGINT vales are cast to int if possible
 
 `BigIntType` casts values retrieved from the database to int if they're inside
@@ -215,9 +220,11 @@ The following classes have been converted to enums:
 1. `Doctrine\DBAL\ColumnCase`,
 2. `Doctrine\DBAL\LockMode`,
 3. `Doctrine\DBAL\ParameterType`,
-4. `Doctrine\DBAL\TransactionIsolationLevel`,
-5. `Doctrine\DBAL\Platforms\DateIntervalUnit`,
-6. `Doctrine\DBAL\Platforms\TrimMode`.
+4. `Doctrine\DBAL\ArrayParameterType`,
+5. `Doctrine\DBAL\TransactionIsolationLevel`,
+6. `Doctrine\DBAL\Platforms\DateIntervalUnit`,
+7. `Doctrine\DBAL\Platforms\TrimMode`.
+8. `Doctrine\DBAL\Query\ForUpdate\ConflictResolutionMode`
 
 The corresponding class constants are now instances of their enum type.
 
diff --git a/psalm.xml.dist b/psalm.xml.dist
index c15dddaf5b7..183443139bf 100644
--- a/psalm.xml.dist
+++ b/psalm.xml.dist
@@ -53,10 +53,6 @@
 
                 <!-- TODO for PHPUnit 11 -->
                 <referencedMethod name="PHPUnit\Framework\TestCase::iniSet"/>
-
-                <!-- TODO: remove in 4.0.0 -->
-                <referencedMethod name="Doctrine\DBAL\Platforms\AbstractPlatform::getForUpdateSQL"/>
-                <referencedMethod name="Doctrine\DBAL\Platforms\DB2Platform::getForUpdateSQL"/>
             </errorLevel>
         </DeprecatedMethod>
         <DocblockTypeContradiction>
diff --git a/src/Platforms/AbstractMySQLPlatform.php b/src/Platforms/AbstractMySQLPlatform.php
index 0a0ad9ad6a7..475f6266f86 100644
--- a/src/Platforms/AbstractMySQLPlatform.php
+++ b/src/Platforms/AbstractMySQLPlatform.php
@@ -739,11 +739,6 @@ public function getSetTransactionIsolationSQL(TransactionIsolationLevel $level):
         return 'SET SESSION TRANSACTION ISOLATION LEVEL ' . $this->_getTransactionIsolationLevelSQL($level);
     }
 
-    public function getReadLockSQL(): string
-    {
-        return 'LOCK IN SHARE MODE';
-    }
-
     protected function initializeDoctrineTypeMappings(): void
     {
         $this->doctrineTypeMapping = [
diff --git a/src/Platforms/AbstractPlatform.php b/src/Platforms/AbstractPlatform.php
index 6dcf3ba0ede..2c3928b7ef1 100644
--- a/src/Platforms/AbstractPlatform.php
+++ b/src/Platforms/AbstractPlatform.php
@@ -701,23 +701,6 @@ public function getBitOrComparisonExpression(string $value1, string $value2): st
      */
     abstract public function getCurrentDatabaseExpression(): string;
 
-    /**
-     * Returns the FOR UPDATE expression.
-     *
-     * @deprecated This API is not portable. Use {@link QueryBuilder::forUpdate()}` instead.
-     */
-    public function getForUpdateSQL(): string
-    {
-        Deprecation::triggerIfCalledFromOutside(
-            'doctrine/dbal',
-            'https://github.com/doctrine/dbal/pull/6191',
-            '%s is deprecated as non-portable.',
-            __METHOD__,
-        );
-
-        return 'FOR UPDATE';
-    }
-
     /**
      * Honors that some SQL vendors such as MsSql use table hints for locking instead of the
      * ANSI SQL FOR UPDATE specification.
@@ -729,45 +712,6 @@ public function appendLockHint(string $fromClause, LockMode $lockMode): string
         return $fromClause;
     }
 
-    /**
-     * Returns the SQL snippet to append to any SELECT statement which locks rows in shared read lock.
-     *
-     * This defaults to the ANSI SQL "FOR UPDATE", which is an exclusive lock (Write). Some database
-     * vendors allow to lighten this constraint up to be a real read lock.
-     *
-     * @deprecated This API is not portable.
-     */
-    public function getReadLockSQL(): string
-    {
-        Deprecation::trigger(
-            'doctrine/dbal',
-            'https://github.com/doctrine/dbal/pull/6191',
-            '%s is deprecated as non-portable.',
-            __METHOD__,
-        );
-
-        return $this->getForUpdateSQL();
-    }
-
-    /**
-     * Returns the SQL snippet to append to any SELECT statement which obtains an exclusive lock on the rows.
-     *
-     * The semantics of this lock mode should equal the SELECT .. FOR UPDATE of the ANSI SQL standard.
-     *
-     * @deprecated This API is not portable.
-     */
-    public function getWriteLockSQL(): string
-    {
-        Deprecation::trigger(
-            'doctrine/dbal',
-            'https://github.com/doctrine/dbal/pull/6191',
-            '%s is deprecated as non-portable.',
-            __METHOD__,
-        );
-
-        return $this->getForUpdateSQL();
-    }
-
     /**
      * Returns the SQL snippet to drop an existing table.
      */
diff --git a/src/Platforms/DB2Platform.php b/src/Platforms/DB2Platform.php
index 31cdfb677b7..a00b24bb702 100644
--- a/src/Platforms/DB2Platform.php
+++ b/src/Platforms/DB2Platform.php
@@ -564,12 +564,6 @@ public function createSelectSQLBuilder(): SelectSQLBuilder
         return new DefaultSelectSQLBuilder($this, 'WITH RR USE AND KEEP UPDATE LOCKS', null);
     }
 
-    /** @deprecated This API is not portable. */
-    public function getForUpdateSQL(): string
-    {
-        return ' WITH RR USE AND KEEP UPDATE LOCKS';
-    }
-
     public function getDummySelectSQL(string $expression = '1'): string
     {
         return sprintf('SELECT %s FROM sysibm.sysdummy1', $expression);
diff --git a/src/Platforms/PostgreSQLPlatform.php b/src/Platforms/PostgreSQLPlatform.php
index c080eea72c9..166ee7547fb 100644
--- a/src/Platforms/PostgreSQLPlatform.php
+++ b/src/Platforms/PostgreSQLPlatform.php
@@ -685,11 +685,6 @@ public function getTruncateTableSQL(string $tableName, bool $cascade = false): s
         return $sql;
     }
 
-    public function getReadLockSQL(): string
-    {
-        return 'FOR SHARE';
-    }
-
     protected function initializeDoctrineTypeMappings(): void
     {
         $this->doctrineTypeMapping = [
diff --git a/src/Platforms/SQLServerPlatform.php b/src/Platforms/SQLServerPlatform.php
index 6078fe7baad..506fe52bbea 100644
--- a/src/Platforms/SQLServerPlatform.php
+++ b/src/Platforms/SQLServerPlatform.php
@@ -1096,12 +1096,6 @@ public function appendLockHint(string $fromClause, LockMode $lockMode): string
         };
     }
 
-    /** @deprecated This API is not portable. */
-    public function getForUpdateSQL(): string
-    {
-        return ' ';
-    }
-
     protected function createReservedKeywordsList(): KeywordList
     {
         return new SQLServerKeywords();
diff --git a/src/Platforms/SQLitePlatform.php b/src/Platforms/SQLitePlatform.php
index 0cca9c67eb6..2f91c277328 100644
--- a/src/Platforms/SQLitePlatform.php
+++ b/src/Platforms/SQLitePlatform.php
@@ -415,11 +415,6 @@ public function getTruncateTableSQL(string $tableName, bool $cascade = false): s
         return 'DELETE FROM ' . $tableIdentifier->getQuotedName($this);
     }
 
-    public function getForUpdateSQL(): string
-    {
-        return '';
-    }
-
     /** @internal The method should be only used from within the {@see AbstractPlatform} class hierarchy. */
     public function getInlineColumnCommentSQL(string $comment): string
     {
diff --git a/src/Query/ForUpdate.php b/src/Query/ForUpdate.php
index f511f6404be..24a853e924a 100644
--- a/src/Query/ForUpdate.php
+++ b/src/Query/ForUpdate.php
@@ -4,15 +4,17 @@
 
 namespace Doctrine\DBAL\Query;
 
+use Doctrine\DBAL\Query\ForUpdate\ConflictResolutionMode;
+
 /** @internal */
 final class ForUpdate
 {
     public function __construct(
-        private readonly int $conflictResolutionMode,
+        private readonly ConflictResolutionMode $conflictResolutionMode,
     ) {
     }
 
-    public function getConflictResolutionMode(): int
+    public function getConflictResolutionMode(): ConflictResolutionMode
     {
         return $this->conflictResolutionMode;
     }
diff --git a/src/Query/ForUpdate/ConflictResolutionMode.php b/src/Query/ForUpdate/ConflictResolutionMode.php
index f968f7b941d..f45f774bddc 100644
--- a/src/Query/ForUpdate/ConflictResolutionMode.php
+++ b/src/Query/ForUpdate/ConflictResolutionMode.php
@@ -4,24 +4,15 @@
 
 namespace Doctrine\DBAL\Query\ForUpdate;
 
-final class ConflictResolutionMode
+enum ConflictResolutionMode
 {
     /**
      * Wait for the row to be unlocked
      */
-    public const ORDINARY = 0;
+    case ORDINARY;
 
     /**
      * Skip the row if it is locked
      */
-    public const SKIP_LOCKED = 1;
-
-    /**
-     * This class cannot be instantiated.
-     *
-     * @codeCoverageIgnore
-     */
-    private function __construct()
-    {
-    }
+    case SKIP_LOCKED;
 }
diff --git a/src/Query/QueryBuilder.php b/src/Query/QueryBuilder.php
index a2710592f52..52fc06d88f4 100644
--- a/src/Query/QueryBuilder.php
+++ b/src/Query/QueryBuilder.php
@@ -492,7 +492,7 @@ public function getMaxResults(): ?int
      *
      * @return $this
      */
-    public function forUpdate(int $conflictResolutionMode = ConflictResolutionMode::ORDINARY): self
+    public function forUpdate(ConflictResolutionMode $conflictResolutionMode = ConflictResolutionMode::ORDINARY): self
     {
         $this->forUpdate = new ForUpdate($conflictResolutionMode);
 
diff --git a/tests/Platforms/DB2PlatformTest.php b/tests/Platforms/DB2PlatformTest.php
index a5f17eb76b0..57320ba85d5 100644
--- a/tests/Platforms/DB2PlatformTest.php
+++ b/tests/Platforms/DB2PlatformTest.php
@@ -321,7 +321,6 @@ public function testGeneratesSQLSnippets(): void
         );
 
         self::assertEquals("'1987/05/02' - 10 YEAR", $this->platform->getDateSubYearsExpression("'1987/05/02'", '10'));
-        self::assertEquals(' WITH RR USE AND KEEP UPDATE LOCKS', $this->platform->getForUpdateSQL());
 
         self::assertEquals(
             'LOCATE(substring_column, string_column)',