diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6a35432..238a008 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [11.1.2] - 2025.10.28
+### Fixed
+- Enum with invalid PHP constant value
+- README.md with multiline description in operations
+
 ## [11.1.1] - 2025.09.23
 ### Fixed
 - Acessing nullable enum with `?->value` instead of `->value?->value`
diff --git a/src/Generator/EnumGenerator.php b/src/Generator/EnumGenerator.php
index 8521e0d..373f62a 100644
--- a/src/Generator/EnumGenerator.php
+++ b/src/Generator/EnumGenerator.php
@@ -16,7 +16,7 @@ class EnumGenerator extends MutatorAccessorClassGeneratorAbstract
 
     public static function getCaseName(string $value): string
     {
-        $sanitized = preg_replace('[^A-Z0-9_]', '', strtoupper(str_replace([' ', '-', '/', '.'], '_', $value)));
+        $sanitized = preg_replace('/[^A-Z0-9_]/', '', strtoupper(str_replace([' ', '-', '/', '.'], '_', $value)));
 
         if (is_numeric($sanitized)) {
             return 'V_' . $sanitized;
@@ -76,9 +76,14 @@ private function generateEnumConsts(Field $root): array
 
         $statements = [];
         foreach ($root->getEnumValues() as $value) {
+            $caseName = self::getCaseName((string)$value);
+            if (empty($caseName)) {
+                continue;
+            }
+
             $statements[] = $this
                 ->builder
-                ->enumCase(self::getCaseName((string)$value))
+                ->enumCase($caseName)
                 ->setValue($value);
         }
 
diff --git a/src/Generator/MutatorAccessorClassGeneratorAbstract.php b/src/Generator/MutatorAccessorClassGeneratorAbstract.php
index 864decf..7547460 100644
--- a/src/Generator/MutatorAccessorClassGeneratorAbstract.php
+++ b/src/Generator/MutatorAccessorClassGeneratorAbstract.php
@@ -117,11 +117,13 @@ protected function generateEnumStatements(Field $field): array
         if (!empty($enumValues)) {
             foreach ($enumValues as $enumValue) {
                 if (is_string($enumValue)) {
-                    $constName    = SchemaNaming::getEnumConstName($field, $enumValue);
-                    $statements[] = $this->builder->constant(
-                        $constName,
-                        $this->builder->val($enumValue)
-                    );
+                    $constName = SchemaNaming::getEnumConstName($field, $enumValue);
+                    if (preg_match('/^[a-zA-Z_][a-zA-Z0-9_]*$/', $constName)) {
+                        $statements[] = $this->builder->constant(
+                            $constName,
+                            $this->builder->val($enumValue)
+                        );
+                    }
                 }
             }
         }
diff --git a/template/README.md.twig b/template/README.md.twig
index eac3490..f2c9f2b 100644
--- a/template/README.md.twig
+++ b/template/README.md.twig
@@ -44,7 +44,7 @@ $result  = $client->{{ exampleOperation.name }}($request);
 ### {{ tag }}
 Endpoints:
 {% for operation in operations %}
-- **{{ operation.name }}**{% if operation.description is not empty %} - {{ operation.description }}{% endif %}
+- **{{ operation.name }}**{% if operation.description is not empty %} - {{ operation.description | trim | split('\n') | first }}{% endif %}
 
 {% endfor %}