diff --git a/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/coalesce_non_nullable_param.php.inc b/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/coalesce_non_nullable_param.php.inc
new file mode 100644
index 00000000000..8ed3a9ddf4c
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/coalesce_non_nullable_param.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ArrowFunction\AddArrowFunctionReturnTypeRector\Fixture;
+
+class CoalesceNonNullableParam
+{
+    public function run()
+    {
+        fn (int $value) => $value ?? null;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ArrowFunction\AddArrowFunctionReturnTypeRector\Fixture;
+
+class CoalesceNonNullableParam
+{
+    public function run()
+    {
+        fn (int $value): int => $value ?? null;
+    }
+}
+
+?>
diff --git a/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/coalesce_nullable_param.php.inc b/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/coalesce_nullable_param.php.inc
new file mode 100644
index 00000000000..b77812a4d41
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/coalesce_nullable_param.php.inc
@@ -0,0 +1,27 @@
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ArrowFunction\AddArrowFunctionReturnTypeRector\Fixture;
+
+class CoalesceNullableParam
+{
+    public function run()
+    {
+        fn (?string $value) => $value ?? null;
+    }
+}
+
+?>
+-----
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ArrowFunction\AddArrowFunctionReturnTypeRector\Fixture;
+
+class CoalesceNullableParam
+{
+    public function run()
+    {
+        fn (?string $value): ?string => $value ?? null;
+    }
+}
+
+?>
diff --git a/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/skip_coalesce_mixed.php.inc b/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/skip_coalesce_mixed.php.inc
new file mode 100644
index 00000000000..140121a8ca7
--- /dev/null
+++ b/rules-tests/TypeDeclaration/Rector/ArrowFunction/AddArrowFunctionReturnTypeRector/Fixture/skip_coalesce_mixed.php.inc
@@ -0,0 +1,11 @@
+<?php
+
+namespace Rector\Tests\TypeDeclaration\Rector\ArrowFunction\AddArrowFunctionReturnTypeRector\Fixture;
+
+class SkipCoalesceMixed
+{
+    public function run()
+    {
+        fn (array $attributes) => $attributes['duration'] ?? null;
+    }
+}