diff --git a/composer.json b/composer.json
index 33d1a9032d5..75f2d833dd6 100644
--- a/composer.json
+++ b/composer.json
@@ -102,7 +102,8 @@
             "Rector\\Utils\\RectorGenerator\\": "utils/RectorGenerator/src",
             "Rector\\StrictCodeQuality\\": "packages/StrictCodeQuality/src",
             "Rector\\DynamicTypeAnalysis\\": "packages/DynamicTypeAnalysis/src",
-            "Rector\\PhpDeglobalize\\": "packages/PhpDeglobalize/src"
+            "Rector\\PhpDeglobalize\\": "packages/PhpDeglobalize/src",
+            "Rector\\Phalcon\\": "packages/Phalcon/src"
         }
     },
     "autoload-dev": {
@@ -160,7 +161,8 @@
             "Rector\\ZendToSymfony\\Tests\\": "packages/ZendToSymfony/tests",
             "Rector\\StrictCodeQuality\\Tests\\": "packages/StrictCodeQuality/tests",
             "Rector\\DynamicTypeAnalysis\\Tests\\": "packages/DynamicTypeAnalysis/tests",
-            "Rector\\PhpDeglobalize\\Tests\\": "packages/PhpDeglobalize/tests"
+            "Rector\\PhpDeglobalize\\Tests\\": "packages/PhpDeglobalize/tests",
+            "Rector\\Phalcon\\Tests\\": "packages/Phalcon/tests"
         },
         "classmap": [
             "packages/Symfony/tests/Rector/FrameworkBundle/AbstractToConstructorInjectionRectorSource",
diff --git a/config/set/phalcon/phalcon40.yaml b/config/set/phalcon/phalcon40.yaml
index 37418cdd2ec..849435d180c 100644
--- a/config/set/phalcon/phalcon40.yaml
+++ b/config/set/phalcon/phalcon40.yaml
@@ -114,3 +114,4 @@ services:
     Rector\Renaming\Rector\ConstFetch\RenameConstantRector:
         FILTER_SPECIAL_CHARS: 'FILTER_SPECIAL'
         FILTER_ALPHANUM: 'FILTER_ALNUM'
+    Rector\Phalcon\Rector\Assign\FlashWithCssClassesToExtraCallRector: ~
diff --git a/packages/Phalcon/src/Rector/Assign/FlashWithCssClassesToExtraCallRector.php b/packages/Phalcon/src/Rector/Assign/FlashWithCssClassesToExtraCallRector.php
new file mode 100644
index 00000000000..c5a6fde98c1
--- /dev/null
+++ b/packages/Phalcon/src/Rector/Assign/FlashWithCssClassesToExtraCallRector.php
@@ -0,0 +1,88 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Phalcon\Rector\Assign;
+
+use PhpParser\Node;
+use PhpParser\Node\Expr\Assign;
+use Rector\Rector\AbstractRector;
+use Rector\RectorDefinition\CodeSample;
+use Rector\RectorDefinition\RectorDefinition;
+
+/**
+ * @see https://github.com/rectorphp/rector/issues/2408#issue-534441142
+ *
+ * @see \Rector\Phalcon\Tests\Rector\Assign\FlashWithCssClassesToExtraCallRector\FlashWithCssClassesToExtraCallRectorTest
+ */
+final class FlashWithCssClassesToExtraCallRector extends AbstractRector
+{
+    public function getDefinition(): RectorDefinition
+    {
+        return new RectorDefinition('Add $cssClasses in Flash to separated method call', [
+            new CodeSample(
+                <<<'PHP'
+class SomeClass {
+    public function run()
+    {
+        $cssClasses = [];
+        $flash = new Phalcon\Flash($cssClasses);
+    }
+}
+PHP
+,
+                <<<'PHP'
+class SomeClass {
+    public function run()
+    {
+        $cssClasses = [];
+        $flash = new Phalcon\Flash();
+        $flash->setCssClasses($cssClasses);
+    }
+}
+PHP
+
+            ),
+        ]);
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getNodeTypes(): array
+    {
+        return [Assign::class];
+    }
+
+    /**
+     * @param Assign $node
+     */
+    public function refactor(Node $node): ?Node
+    {
+        if (! $node->expr instanceof Node\Expr\New_) {
+            return null;
+        }
+
+        if (! $this->isName($node->expr->class, 'Phalcon\Flash')) {
+            return null;
+        }
+
+        if (! isset($node->expr->args[0])) {
+            return null;
+        }
+
+        $argument = $node->expr->args[0];
+
+        // remove arg
+        unset($node->expr->args[0]);
+
+        // change the node
+
+        $variable = $node->var;
+        $setCssClassesMethodCall = new Node\Expr\MethodCall($variable, 'setCssClasses', [$argument]);
+
+        $this->addNodeAfterNode($setCssClassesMethodCall, $node);
+
+        return $node;
+    }
+}
diff --git a/packages/Phalcon/tests/Rector/Assign/FlashWithCssClassesToExtraCallRector/Fixture/fixture.php.inc b/packages/Phalcon/tests/Rector/Assign/FlashWithCssClassesToExtraCallRector/Fixture/fixture.php.inc
new file mode 100644
index 00000000000..1832df4a19e
--- /dev/null
+++ b/packages/Phalcon/tests/Rector/Assign/FlashWithCssClassesToExtraCallRector/Fixture/fixture.php.inc
@@ -0,0 +1,28 @@
+<?php
+
+namespace Rector\Phalcon\Tests\Rector\Assign\FlashWithCssClassesToExtraCallRector\Fixture;
+
+class SomeClass {
+    public function run()
+    {
+        $cssClasses = [];
+        $flash = new \Phalcon\Flash($cssClasses);
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Phalcon\Tests\Rector\Assign\FlashWithCssClassesToExtraCallRector\Fixture;
+
+class SomeClass {
+    public function run()
+    {
+        $cssClasses = [];
+        $flash = new \Phalcon\Flash();
+        $flash->setCssClasses($cssClasses);
+    }
+}
+
+?>
diff --git a/packages/Phalcon/tests/Rector/Assign/FlashWithCssClassesToExtraCallRector/FlashWithCssClassesToExtraCallRectorTest.php b/packages/Phalcon/tests/Rector/Assign/FlashWithCssClassesToExtraCallRector/FlashWithCssClassesToExtraCallRectorTest.php
new file mode 100644
index 00000000000..0704446ce83
--- /dev/null
+++ b/packages/Phalcon/tests/Rector/Assign/FlashWithCssClassesToExtraCallRector/FlashWithCssClassesToExtraCallRectorTest.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Phalcon\Tests\Rector\Assign\FlashWithCssClassesToExtraCallRector;
+
+use Iterator;
+use Rector\Phalcon\Rector\Assign\FlashWithCssClassesToExtraCallRector;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class FlashWithCssClassesToExtraCallRectorTest extends AbstractRectorTestCase
+{
+    /**
+     * @dataProvider provideDataForTest()
+     */
+    public function test(string $file): void
+    {
+        $this->doTestFile($file);
+    }
+
+    public function provideDataForTest(): Iterator
+    {
+        return $this->yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    protected function getRectorClass(): string
+    {
+        return FlashWithCssClassesToExtraCallRector::class;
+    }
+}
diff --git a/rector.yaml b/rector.yaml
index 6bb9ab94135..0022e6f40f7 100644
--- a/rector.yaml
+++ b/rector.yaml
@@ -19,23 +19,22 @@ parameters:
     # @see utils/RectorGenerator/config/config.yaml
     rector_recipe:
         # run "bin/rector create" to create a new Rector + tests from this config
-        package: "Rector"
-        name: "SwapClassMethodArgumentsRector"
+        package: "Phalcon"
+        name: "FlashWithCssClassesToExtraCallRector"
         node_types:
             # put main node first, it is used to create namespace
-            - "StaticCall"
-            - "MethodCall"
-            - "ClassMethod"
+            - "Assign"
 
-        description: "Reorder class method arguments, including their calls"
+        description: "Add $cssClasses in Flash to separated method call"
         code_before: >
             <?php
 
             class SomeClass
             {
-                public static function run($first, $second)
+                public function run()
                 {
-                    self::run($first, $second);
+                    $cssClasses = [];
+                    $flash = new Phalcon\Flash($cssClasses);
                 }
             }
 
@@ -44,12 +43,14 @@ parameters:
 
             class SomeClass
             {
-                public static function run($second, $first)
+                public function run()
                 {
-                    self::run($second, $first);
+                    $cssClasses = [];
+                    $flash = new Phalcon\Flash();
+                    $flash->setCssClasses($cssClasses);
                 }
             }
 
         source: # e.g. link to RFC or headline in upgrade guide, 1 or more in the list
-            - ""
-        set: "" # e.g. symfony30, target config to append this rector to
+            - "https://github.com/rectorphp/rector/issues/2408#issue-534441142"
+        set: "phalcon40" # e.g. symfony30, target config to append this rector to