diff --git a/README.md b/README.md
index aa2cf0e..23ed13c 100644
--- a/README.md
+++ b/README.md
@@ -151,6 +151,36 @@ $redactor = (new ArrayRedactor($login, ['password', 'session_id']))->ink(null)->
 ];
 ```
 
+If the value you pass into the third constructor argument or the `->ink()` method is callable, it will be invoked when redacting each value, and its return value will be used as the redacted value in the result:
+
+```php
+$login = [
+    'email' => 'john_doe@domain.com',
+    'password' => 'secret123',
+    'data' => [
+        'session_id' => 'z481jf0an4kasnc8a84aj831'
+    ],
+];
+
+$ink_function = function($val, $key) {
+    return $key === 'email' ? substr($val, stripos($val, '@')) : '[REDACTED]';
+};
+
+$redactor = (new ArrayRedactor($login, ['email', 'password', 'session_id'], $ink_function))->redact();
+// or...
+$redactor = (new ArrayRedactor($login, ['email', 'password', 'session_id']))->ink($ink_function)->redact();
+
+// $redactor will return:
+[
+    'email' => '@domain.com',
+    'password' => '[REDACTED]'
+    'data' => [
+        'session_id' => '[REDACTED]'
+    ],
+];
+
+```
+
 You can call the ``ArrayRedactor`` as a function and the magic ``__invoke()`` method will call the ``redact`` method for you.
 
 ```php
diff --git a/composer.json b/composer.json
index dd6fe96..c063b7a 100644
--- a/composer.json
+++ b/composer.json
@@ -28,10 +28,10 @@
         ]
     },
     "require": {
-        "php": ">=5.6"
+        "php": ">=7.4|>=8.0"
     },
     "require-dev": {
-      "phpunit/phpunit": "^6.4"
+      "phpunit/phpunit": "^9"
     },
     "autoload-dev": {
         "psr-4": {
diff --git a/src/ArrayRedactor.php b/src/ArrayRedactor.php
index 76cac82..08d1a55 100644
--- a/src/ArrayRedactor.php
+++ b/src/ArrayRedactor.php
@@ -77,7 +77,7 @@ public function keys($keys = [])
      */
     public function ink($ink = '[REDACTED]')
     {
-        $this->ink = is_callable($ink) ? $ink() : $ink;
+        $this->ink = $ink;
         return $this;
     }
 
@@ -99,7 +99,7 @@ public function redact()
         // Recursively traverse the array and redact the specified keys
         array_walk_recursive($this->content, function (&$value, $key) {
             if (in_array($key, $this->keys, true)) {
-                $value = $this->ink;
+                $value = is_callable($this->ink) ? call_user_func($this->ink, $value, $key) : $this->ink;
             }
         });
 
diff --git a/tests/ArrayRedactorTest.php b/tests/ArrayRedactorTest.php
index e854b8e..f9e7494 100644
--- a/tests/ArrayRedactorTest.php
+++ b/tests/ArrayRedactorTest.php
@@ -6,7 +6,7 @@
 
 class ArrayRedactorTest extends TestCase
 {
-    protected function setUp()
+    protected function setUp(): void
     {
     	$this->content = [
     		'email' => 'mtownsend5512@gmail.com',
@@ -98,10 +98,11 @@ public function can_omit_constructor_arguments_in_favor_of_methods()
     /** @test */
     public function can_accept_closure_in_ink()
     {
-        $array = $this->content;
-        $result = (new ArrayRedactor())->content($this->content)->keys(['email'])->ink(function() use ($array) {
-            return substr($array['email'], stripos($array['email'], '@'));
-        })->redact();
+        $func = function(string $val, string $key): string {
+            return $key === 'email' ? substr($val, stripos($val, '@')) : $val;
+        };
+
+        $result = (new ArrayRedactor())->content($this->content)->keys(['email'])->ink($func)->redact();
         $this->assertEquals(array_merge($this->content, [
             'email' => '@gmail.com'
         ]), $result);