diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/DowngradeStrContainsWithMultibyteNeedleRectorTest.php b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/DowngradeStrContainsWithMultibyteNeedleRectorTest.php
new file mode 100644
index 00000000..de0c2219
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/DowngradeStrContainsWithMultibyteNeedleRectorTest.php
@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector;
+
+use Iterator;
+use PHPUnit\Framework\Attributes\DataProvider;
+use Rector\Testing\PHPUnit\AbstractRectorTestCase;
+
+final class DowngradeStrContainsWithMultibyteNeedleRectorTest extends AbstractRectorTestCase
+{
+    #[DataProvider('provideData')]
+    public function test(string $filePath): void
+    {
+        $this->doTestFile($filePath);
+    }
+
+    public static function provideData(): Iterator
+    {
+        return self::yieldFilesFromDirectory(__DIR__ . '/Fixture');
+    }
+
+    public function provideConfigFilePath(): string
+    {
+        return __DIR__ . '/config/configured_rule.php';
+    }
+}
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/fixture_equal.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/fixture_equal.php.inc
new file mode 100644
index 00000000..c120cd9a
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/fixture_equal.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class Fixture
+{
+    public function run()
+    {
+        $isMatch = str_contains('😊abc', '😊a');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class Fixture
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a') !== false;
+    }
+}
+
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/identical_mb_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/identical_mb_strpos.php.inc
new file mode 100644
index 00000000..f3b8cab8
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/identical_mb_strpos.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class IdenticalStrpos
+{
+    public function run()
+    {
+        $isMatch = !str_contains('abc😊', '😊a');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class IdenticalStrpos
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('abc😊', '😊a') === false;
+    }
+}
+
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_equal_mb_strstr.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_equal_mb_strstr.php.inc
new file mode 100644
index 00000000..db9bece0
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_equal_mb_strstr.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class IdenticalStrstr
+{
+    public function run()
+    {
+        $isMatch = !str_contains('😊abc', '😊a');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class IdenticalStrstr
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a') === false;
+    }
+}
+
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_str_contains.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_str_contains.php.inc
new file mode 100644
index 00000000..896d32f5
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_str_contains.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+final class NoStrContains
+{
+    public function run()
+    {
+        return ! str_contains('😊abc', 'b😊');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+final class NoStrContains
+{
+    public function run()
+    {
+        return mb_strpos('😊abc', 'b😊') === false;
+    }
+}
+
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_strstr.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_strstr.php.inc
new file mode 100644
index 00000000..db9bece0
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/not_strstr.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class IdenticalStrstr
+{
+    public function run()
+    {
+        $isMatch = !str_contains('😊abc', '😊a');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class IdenticalStrstr
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a') === false;
+    }
+}
+
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_equal_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_equal_strpos.php.inc
new file mode 100644
index 00000000..27ae5638
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_equal_strpos.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetStrpos
+{
+    public function run()
+    {
+        $isMatch = str_contains(mb_substr('😊abc', 1), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetStrpos
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a', 1) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_expression_equal_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_expression_equal_strpos.php.inc
new file mode 100644
index 00000000..6b07e619
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_expression_equal_strpos.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetExpressionStrpos
+{
+    public function run()
+    {
+        $offset = 1;
+        $isMatch = str_contains(mb_substr('😊abc', $offset + 1), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetExpressionStrpos
+{
+    public function run()
+    {
+        $offset = 1;
+        $isMatch = mb_strpos('😊abc', '😊a', $offset + 1) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_expression_mb_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_expression_mb_strpos.php.inc
new file mode 100644
index 00000000..6b07e619
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_expression_mb_strpos.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetExpressionStrpos
+{
+    public function run()
+    {
+        $offset = 1;
+        $isMatch = str_contains(mb_substr('😊abc', $offset + 1), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetExpressionStrpos
+{
+    public function run()
+    {
+        $offset = 1;
+        $isMatch = mb_strpos('😊abc', '😊a', $offset + 1) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_negative_equal_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_negative_equal_strpos.php.inc
new file mode 100644
index 00000000..a80c166c
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_negative_equal_strpos.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetNegativeStrpos
+{
+    public function run()
+    {
+        $isMatch = str_contains(mb_substr('😊abc', -1), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetNegativeStrpos
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a', -1) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_negative_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_negative_strpos.php.inc
new file mode 100644
index 00000000..a80c166c
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_negative_strpos.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetNegativeStrpos
+{
+    public function run()
+    {
+        $isMatch = str_contains(mb_substr('😊abc', -1), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetNegativeStrpos
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a', -1) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_strpos.php.inc
new file mode 100644
index 00000000..27ae5638
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_strpos.php.inc
@@ -0,0 +1,25 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetStrpos
+{
+    public function run()
+    {
+        $isMatch = str_contains(mb_substr('😊abc', 1), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetStrpos
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a', 1) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_equal_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_equal_strpos.php.inc
new file mode 100644
index 00000000..03d1a5b3
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_equal_strpos.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetVariableStrpos
+{
+    public function run()
+    {
+        $offset = 1;
+        $isMatch = str_contains(mb_substr('😊abc', $offset), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetVariableStrpos
+{
+    public function run()
+    {
+        $offset = 1;
+        $isMatch = mb_strpos('😊abc', '😊a', $offset) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_strpos.php.inc
new file mode 100644
index 00000000..0e4ff70a
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_strpos.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetVariableStrpos
+{
+    public function run()
+    {
+        $offset = 1;
+        $isMatch = str_contains(mb_substr('😊abc', $offset), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetVariableStrpos
+{
+    public function run()
+    {
+        $offset = 1;
+        $isMatch = mb_strpos('😊abc', '😊a', $offset) !== false;
+    }
+}
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_zero_equal_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_zero_equal_strpos.php.inc
new file mode 100644
index 00000000..38c8d610
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_zero_equal_strpos.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetVariableZeroStrpos
+{
+    public function run()
+    {
+        $offset = 0;
+        $isMatch = str_contains(mb_substr('😊abc', $offset), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetVariableZeroStrpos
+{
+    public function run()
+    {
+        $offset = 0;
+        $isMatch = mb_strpos('😊abc', '😊a', $offset) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_zero_strpos.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_zero_strpos.php.inc
new file mode 100644
index 00000000..38c8d610
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/offset_variable_zero_strpos.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetVariableZeroStrpos
+{
+    public function run()
+    {
+        $offset = 0;
+        $isMatch = str_contains(mb_substr('😊abc', $offset), '😊a');
+    }
+}
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class OffsetVariableZeroStrpos
+{
+    public function run()
+    {
+        $offset = 0;
+        $isMatch = mb_strpos('😊abc', '😊a', $offset) !== false;
+    }
+}
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_fixture_equal.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_fixture_equal.php.inc
new file mode 100644
index 00000000..27b23e07
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_fixture_equal.php.inc
@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class Fixture
+{
+    public function run()
+    {
+        $isMatch = str_contains('abc', 'a');
+    }
+}
+
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_str_contains.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_str_contains.php.inc
new file mode 100644
index 00000000..492c4926
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_str_contains.php.inc
@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+final class StrContains
+{
+    public function run()
+    {
+        str_contains('😊abc', 'b');
+    }
+}
+
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_str_contains.php_with_mixed.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_str_contains.php_with_mixed.php.inc
new file mode 100644
index 00000000..d5bd6f0d
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/skip_str_contains.php_with_mixed.php.inc
@@ -0,0 +1,14 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+final class StrContainsPhpWithMixed
+{
+    public function run($haystack, $needle)
+    {
+        str_contains($haystack, 'ab');
+        str_contains('😊abc', $needle);
+    }
+}
+
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/strstr.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/strstr.php.inc
new file mode 100644
index 00000000..dab93a74
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/strstr.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class Strstr
+{
+    public function run()
+    {
+        $isMatch = str_contains('😊abc', '😊a');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class Strstr
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a') !== false;
+    }
+}
+
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/the_other_way.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/the_other_way.php.inc
new file mode 100644
index 00000000..1fb94d54
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/the_other_way.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class TheOtherWay
+{
+    public function run()
+    {
+        $isMatch = str_contains('😊abc', '😊a');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class TheOtherWay
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a') !== false;
+    }
+}
+
+?>
\ No newline at end of file
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/the_other_way_equal.php.inc b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/the_other_way_equal.php.inc
new file mode 100644
index 00000000..969483ec
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/Fixture/the_other_way_equal.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class TheOtherWay
+{
+    public function run()
+    {
+        $isMatch = str_contains('😊abc', '😊a');
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\Fixture;
+
+class TheOtherWay
+{
+    public function run()
+    {
+        $isMatch = mb_strpos('😊abc', '😊a') !== false;
+    }
+}
+
+?>
diff --git a/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/config/configured_rule.php b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/config/configured_rule.php
new file mode 100644
index 00000000..b46f20b2
--- /dev/null
+++ b/rules-tests/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector/config/configured_rule.php
@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->rule(DowngradeStrContainsWithMultibyteNeedleRector::class);
+};
diff --git a/rules/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector.php b/rules/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector.php
new file mode 100644
index 00000000..00d16022
--- /dev/null
+++ b/rules/DowngradePhp80/Rector/FuncCall/DowngradeStrContainsWithMultibyteNeedleRector.php
@@ -0,0 +1,147 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rector\DowngradePhp80\Rector\FuncCall;
+
+use PhpParser\Node;
+use PhpParser\Node\Arg;
+use PhpParser\Node\Expr\BinaryOp\Identical;
+use PhpParser\Node\Expr\BinaryOp\NotIdentical;
+use PhpParser\Node\Expr\BooleanNot;
+use PhpParser\Node\Scalar\String_;
+use PhpParser\Node\Expr\FuncCall;
+use Rector\Rector\AbstractRector;
+use Symplify\RuleDocGenerator\ValueObject\CodeSample\CodeSample;
+use Symplify\RuleDocGenerator\ValueObject\RuleDefinition;
+
+/**
+ * @changelog https://wiki.php.net/rfc/str_contains
+ *
+ * @see \Rector\Tests\DowngradePhp80\Rector\FuncCall\DowngradeStrContainsWithMultibyteNeedleRector\DowngradeStrContainsWithMultibyteNeedleRectorTest
+ */
+final class DowngradeStrContainsWithMultibyteNeedleRector extends AbstractRector
+{
+    public function getRuleDefinition(): RuleDefinition
+    {
+        return new RuleDefinition(
+            'Replace str_contains() with mb_strpos() !== false',
+            [
+                new CodeSample(
+                    <<<'CODE_SAMPLE'
+class SomeClass
+{
+    public function run()
+    {
+        return str_contains('😊abc', '😊a');
+    }
+}
+CODE_SAMPLE
+                    ,
+                    <<<'CODE_SAMPLE'
+class SomeClass
+{
+    public function run()
+    {
+        return mb_strpos('😊abc', '😊a') !== false;
+    }
+}
+CODE_SAMPLE
+                ),
+            ]
+        );
+    }
+
+    /**
+     * @return array<class-string<Node>>
+     */
+    public function getNodeTypes(): array
+    {
+        return [FuncCall::class, BooleanNot::class];
+    }
+
+    /**
+     * @param FuncCall|BooleanNot $node
+     * @return Identical|NotIdentical|null The refactored node.
+     */
+    public function refactor(Node $node): Identical | NotIdentical | null
+    {
+        $funcCall = $this->matchStrContainsOrNotStrContains($node);
+
+        if (! $funcCall instanceof FuncCall) {
+            return null;
+        }
+
+        if ($funcCall->isFirstClassCallable()) {
+            return null;
+        }
+
+        $args = $funcCall->getArgs();
+        if (count($args) < 2) {
+            return null;
+        }
+
+        $haystack = $args[0]->value;
+        $needle = $args[1]->value;
+        $offset = null;
+
+        if ($haystack instanceof FuncCall) {
+
+            if (! $this->isName($haystack->name, 'mb_substr')) {
+                return null;
+            }
+
+            if ($haystack->isFirstClassCallable()) {
+                return null;
+            }
+
+            $substrArg = $haystack->getArgs();
+            if (isset($substrArg[0]) && ! $substrArg[0] instanceof Arg) {
+                return null;
+            }
+
+            if (isset($substrArg[1]) && ! $substrArg[1] instanceof Arg) {
+                return null;
+            }
+
+            $haystack = $substrArg[0];
+            $offset = $substrArg[1];
+        }
+
+        if (!$needle instanceof String_) {
+            return null;
+        }
+
+        if(strlen($needle->value) === mb_strlen($needle->value)){
+            return null;
+        }
+           
+        if ($offset instanceof Arg) {
+            $funcCall = $this->nodeFactory->createFuncCall('mb_strpos', [$haystack, $needle, $offset]);
+        }
+
+        if (! $offset instanceof Arg) {
+            $funcCall = $this->nodeFactory->createFuncCall('mb_strpos', [$haystack, $needle]);
+        }
+
+        if ($node instanceof BooleanNot) {
+            return new Identical($funcCall, $this->nodeFactory->createFalse());
+        }
+
+        return new NotIdentical($funcCall, $this->nodeFactory->createFalse());
+    }
+
+    private function matchStrContainsOrNotStrContains(FuncCall | BooleanNot $expr): ?FuncCall
+    {
+        $expr = ($expr instanceof BooleanNot) ? $expr->expr : $expr;
+        if (! $expr instanceof FuncCall) {
+            return null;
+        }
+
+        if (! $this->isName($expr, 'str_contains')) {
+            return null;
+        }
+
+        return $expr;
+    }
+}