diff --git a/rules-tests/CodeQuality/Rector/Class_/InlineConstructorDefaultToPropertyRector/Fixture/do_not_change_readonly.php.inc b/rules-tests/CodeQuality/Rector/Class_/InlineConstructorDefaultToPropertyRector/Fixture/do_not_change_readonly.php.inc
new file mode 100644
index 00000000000..4d7296a7f14
--- /dev/null
+++ b/rules-tests/CodeQuality/Rector/Class_/InlineConstructorDefaultToPropertyRector/Fixture/do_not_change_readonly.php.inc
@@ -0,0 +1,13 @@
+<?php
+
+namespace Rector\Tests\CodeQuality\Rector\Class_\InlineConstructorDefaultToPropertyRector\Fixture;
+
+final class DoNotChangeReadonly
+{
+    private readonly string $name;
+
+    public function __construct()
+    {
+        $this->name = 'John';
+    }
+}
diff --git a/rules/CodeQuality/Rector/Class_/InlineConstructorDefaultToPropertyRector.php b/rules/CodeQuality/Rector/Class_/InlineConstructorDefaultToPropertyRector.php
index 67b12d06630..6b76a991d95 100644
--- a/rules/CodeQuality/Rector/Class_/InlineConstructorDefaultToPropertyRector.php
+++ b/rules/CodeQuality/Rector/Class_/InlineConstructorDefaultToPropertyRector.php
@@ -83,6 +83,10 @@ public function refactor(Node $node): ?Node
                 continue;
             }
 
+            if ($property->isReadonly()) {
+                continue;
+            }
+
             $propertyProperty = $property->props[0];
             $propertyProperty->default = $defaultPropertyExprAssign->getDefaultExpr();