diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8670a19..3c71722 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,25 @@ All notable changes to this project will be documented in this file, in reverse
 
 - Nothing.
 
+## 0.1.1 - 2020-12-03
+
+
+-----
+
+### Release Notes for [0.1.1](https://github.com/open-code-modeling/php-filter/milestone/2)
+
+0.1.x bugfix release (patch)
+
+### 0.1.1
+
+- Total issues resolved: **1**
+- Total pull requests resolved: **0**
+- Total contributors: **1**
+
+#### bug
+
+ - [10: Method name filter and upper letters issue](https://github.com/open-code-modeling/php-filter/issues/10) thanks to @sandrokeil
+
 ## 0.1.0 - 2020-11-30
 
 
diff --git a/src/Filter/UpperToLower.php b/src/Filter/UpperToLower.php
new file mode 100644
index 0000000..7d40bd6
--- /dev/null
+++ b/src/Filter/UpperToLower.php
@@ -0,0 +1,25 @@
+<?php
+
+/**
+ * @see       https://github.com/open-code-modeling/php-filter for the canonical source repository
+ * @copyright https://github.com/open-code-modeling/php-filter/blob/master/COPYRIGHT.md
+ * @license   https://github.com/open-code-modeling/php-filter/blob/master/LICENSE.md MIT License
+ */
+
+declare(strict_types=1);
+
+namespace OpenCodeModeling\Filter\Filter;
+
+final class UpperToLower extends AbstractFilter
+{
+    public function __invoke(string $value): string
+    {
+        $value = ($this->filter)($value);
+
+        if (1 === \preg_match('/^[A-Z]+$/', $value)) {
+            return \strtolower($value);
+        }
+
+        return $value;
+    }
+}
diff --git a/src/FilterFactory.php b/src/FilterFactory.php
index 2e62fc4..44c4b94 100644
--- a/src/FilterFactory.php
+++ b/src/FilterFactory.php
@@ -16,6 +16,7 @@
 use OpenCodeModeling\Filter\Filter\LowerCaseFirst;
 use OpenCodeModeling\Filter\Filter\NormalizeLabel;
 use OpenCodeModeling\Filter\Filter\UpperCaseFirst;
+use OpenCodeModeling\Filter\Filter\UpperToLower;
 
 final class FilterFactory
 {
@@ -93,7 +94,7 @@ public static function propertyNameFilter(): callable
      */
     public static function methodNameFilter(): callable
     {
-        return new LowerCaseFirst(self::normalizeFilter());
+        return new LowerCaseFirst(self::normalizeFilter(new UpperToLower()));
     }
 
     /**
diff --git a/tests/FilterFactoryTest.php b/tests/FilterFactoryTest.php
index 59dae54..bbf45ab 100644
--- a/tests/FilterFactoryTest.php
+++ b/tests/FilterFactoryTest.php
@@ -36,6 +36,15 @@ public function it_filters_method_name(string $label): void
         $this->assertSame('addBuilding', ($filter)($label));
     }
 
+    /**
+     * @test
+     */
+    public function it_filters_method_name_with_only_upper_letters(): void
+    {
+        $filter = FilterFactory::methodNameFilter();
+        $this->assertSame('ny', ($filter)('NY'));
+    }
+
     /**
      * @test
      * @dataProvider providerForLabel