diff --git a/docs/book/v3/word.md b/docs/book/v3/word.md
index cc95b4ad..ec917fdf 100644
--- a/docs/book/v3/word.md
+++ b/docs/book/v3/word.md
@@ -323,3 +323,22 @@ print $filter->filter('this_is_my_content');
 ```
 
 The above example returns `this-is-my-content`.
+
+## UnderscoreToStudlyCase
+
+This filter modifies a given string such that `words_with_underscores` are
+converted to `wordsWithUnderscores`.
+
+### Supported Options
+
+There are no additional options for `Laminas\Filter\Word\UnderscoreToStudlyCase`:
+
+### Basic Usage
+
+```php
+$filter = new Laminas\Filter\Word\UnderscoreToStudlyCase();
+
+print $filter->filter('this_is_my_content');
+```
+
+The above example returns `thisIsMyContent`.
diff --git a/psalm-baseline.xml b/psalm-baseline.xml
index 7b00704d..103558e3 100644
--- a/psalm-baseline.xml
+++ b/psalm-baseline.xml
@@ -635,22 +635,6 @@
       <code><![CDATA[$requestedName]]></code>
     </UnusedParam>
   </file>
-  <file src="src/Word/UnderscoreToStudlyCase.php">
-    <MissingClosureParamType>
-      <code><![CDATA[$value]]></code>
-    </MissingClosureParamType>
-    <MissingClosureReturnType>
-      <code><![CDATA[static function ($value) {]]></code>
-    </MissingClosureReturnType>
-    <MixedArgument>
-      <code><![CDATA[$value]]></code>
-      <code><![CDATA[$value]]></code>
-      <code><![CDATA[$value]]></code>
-    </MixedArgument>
-    <MixedReturnStatement>
-      <code><![CDATA[is_array($value) ? array_map($lowerCaseFirst, $value) : $lowerCaseFirst($value)]]></code>
-    </MixedReturnStatement>
-  </file>
   <file src="test/AllowListTest.php">
     <PossiblyUnusedMethod>
       <code><![CDATA[defaultTestProvider]]></code>
@@ -1008,14 +992,4 @@
       <code><![CDATA[$filtered]]></code>
     </MixedAssignment>
   </file>
-  <file src="test/Word/UnderscoreToStudlyCaseTest.php">
-    <MixedAssignment>
-      <code><![CDATA[$filtered]]></code>
-      <code><![CDATA[$filtered]]></code>
-      <code><![CDATA[$filtered]]></code>
-      <code><![CDATA[$filtered]]></code>
-      <code><![CDATA[$filtered]]></code>
-      <code><![CDATA[$filtered]]></code>
-    </MixedAssignment>
-  </file>
 </files>
diff --git a/src/Word/UnderscoreToStudlyCase.php b/src/Word/UnderscoreToStudlyCase.php
index 8dd81653..8da1b489 100755
--- a/src/Word/UnderscoreToStudlyCase.php
+++ b/src/Word/UnderscoreToStudlyCase.php
@@ -4,30 +4,18 @@
 
 namespace Laminas\Filter\Word;
 
-use Laminas\Stdlib\StringUtils;
+use Laminas\Filter\FilterInterface;
+use Laminas\Filter\ScalarOrArrayFilterCallback;
 
-use function array_map;
 use function is_array;
 use function is_scalar;
 use function mb_strlen;
 use function mb_strtolower;
 use function mb_substr;
 
-/**
- * @psalm-type Options = array{
- *     separator?: string,
- *     ...
- * }
- * @template TOptions of Options
- * @template-extends UnderscoreToCamelCase<TOptions>
- */
-final class UnderscoreToStudlyCase extends UnderscoreToCamelCase
+/** @implements FilterInterface<string|array<array-key, string|mixed>> */
+final class UnderscoreToStudlyCase implements FilterInterface
 {
-    /**
-     * Defined by Laminas\Filter\Filter
-     *
-     * @psalm-return ($value is scalar ? string : $value is array ? array : mixed)
-     */
     public function filter(mixed $value): mixed
     {
         if (! is_scalar($value) && ! is_array($value)) {
@@ -35,19 +23,22 @@ public function filter(mixed $value): mixed
         }
 
         /** @var string|array $value */
-        $value          = parent::filter($value);
-        $lowerCaseFirst = 'lcfirst';
+        $value = (new SeparatorToCamelCase('_'))->filter($value);
 
-        if (StringUtils::hasPcreUnicodeSupport()) {
-            $lowerCaseFirst = static function ($value) {
-                if (0 === mb_strlen($value)) {
-                    return $value;
+        return ScalarOrArrayFilterCallback::applyRecursively(
+            $value,
+            function (string $input): string {
+                if (0 === mb_strlen($input)) {
+                    return $input;
                 }
 
-                return mb_strtolower(mb_substr($value, 0, 1)) . mb_substr($value, 1);
-            };
-        }
+                return mb_strtolower(mb_substr($input, 0, 1)) . mb_substr($input, 1);
+            }
+        );
+    }
 
-        return is_array($value) ? array_map($lowerCaseFirst, $value) : $lowerCaseFirst($value);
+    public function __invoke(mixed $value): mixed
+    {
+        return $this->filter($value);
     }
 }