diff --git a/src/Driver/AbstractMySQLDriver.php b/src/Driver/AbstractMySQLDriver.php
index 07a01726d9b..4610bde3bd8 100644
--- a/src/Driver/AbstractMySQLDriver.php
+++ b/src/Driver/AbstractMySQLDriver.php
@@ -63,10 +63,7 @@ public function getDatabasePlatform(ServerVersionProvider $versionProvider): Abs
             return new MySQL8013Platform();
         }
 
-        if (
-            version_compare($version, '8.0.0', '>=')
-            && version_compare($version, '8.0.13', '<')
-        ) {
+        if (version_compare($version, '8.0.0', '>=')) {
             return new MySQL80Platform();
         }
 
diff --git a/src/Platforms/AbstractPlatform.php b/src/Platforms/AbstractPlatform.php
index 1fa69c347b6..d2128186c56 100644
--- a/src/Platforms/AbstractPlatform.php
+++ b/src/Platforms/AbstractPlatform.php
@@ -802,7 +802,7 @@ private function buildCreateTableSQL(Table $table, bool $createForeignKeys): arr
                     'but platform "%s" does not support functional indexes.',
                     $index->getName(),
                     $table->getName(),
-                    substr(static::class, (int) strrpos(static::class, '\\') + 1),
+                    get_debug_type($this),
                 ));
             }
 
@@ -1099,7 +1099,7 @@ public function getCreateIndexSQL(Index $index, string $table): string
                 'but platform "%s" does not support functional indexes.',
                 $name,
                 $table,
-                substr(static::class, (int) strrpos(static::class, '\\') + 1),
+                get_debug_type($this),
             ));
         }
 
@@ -1560,7 +1560,7 @@ public function getIndexDeclarationSQL(Index $index): string
                 'Index "%s" contains a functional part, ' .
                 'but platform "%s" does not support functional indexes.',
                 $index->getName(),
-                substr(static::class, (int) strrpos(static::class, '\\') + 1),
+                get_debug_type($this),
             ));
         }
 
diff --git a/src/Platforms/MySQL8013Platform.php b/src/Platforms/MySQL8013Platform.php
index 5e87ffe53c5..2b2feaf0428 100644
--- a/src/Platforms/MySQL8013Platform.php
+++ b/src/Platforms/MySQL8013Platform.php
@@ -8,6 +8,7 @@
  * Provides features of the MySQL since 8.0.13 database platform.
  *
  * Note: Should not be used with versions prior to 8.0.13.
+ * @deprecated This class will be removed once support for MySQL 8.0.13 is dropped.
  */
 class MySQL8013Platform extends MySQL80Platform
 {
diff --git a/src/Platforms/MySQL84Platform.php b/src/Platforms/MySQL84Platform.php
index 0c304318c62..15d0083840f 100644
--- a/src/Platforms/MySQL84Platform.php
+++ b/src/Platforms/MySQL84Platform.php
@@ -16,4 +16,9 @@ protected function createReservedKeywordsList(): KeywordList
     {
         return new MySQL84Keywords();
     }
+
+    public function supportsFunctionalIndex(): bool
+    {
+        return true;
+    }
 }
diff --git a/src/Platforms/SQLitePlatform.php b/src/Platforms/SQLitePlatform.php
index 41f4e92f11b..3144747a1f5 100644
--- a/src/Platforms/SQLitePlatform.php
+++ b/src/Platforms/SQLitePlatform.php
@@ -568,7 +568,7 @@ public function getCreateIndexSQL(Index $index, string $table): string
                 'but platform "%s" does not support functional indexes.',
                 $name,
                 $table,
-                substr(static::class, (int) strrpos(static::class, '\\') + 1),
+                get_debug_type($this),
             ));
         }
 
diff --git a/src/Schema/PostgreSQLSchemaManager.php b/src/Schema/PostgreSQLSchemaManager.php
index f7c39fd7bb6..f4ebfd82ab4 100644
--- a/src/Schema/PostgreSQLSchemaManager.php
+++ b/src/Schema/PostgreSQLSchemaManager.php
@@ -161,7 +161,7 @@ protected function _getPortableTableIndexesList(array $tableIndexes, string $tab
     {
         $buffer = [];
         foreach ($tableIndexes as $row) {
-            $indexColumns = json_decode($row['index_columns'], true);
+            $indexColumns = json_decode($row['index_columns'], true, flags: JSON_THROW_ON_ERROR);
 
             foreach ($indexColumns as $colRow) {
                 $buffer[] = [