diff --git a/modules/openapi-generator/src/main/resources/php-nextgen/model_generic.mustache b/modules/openapi-generator/src/main/resources/php-nextgen/model_generic.mustache
index 4904e3de9f6..ce2670ef0fd 100644
--- a/modules/openapi-generator/src/main/resources/php-nextgen/model_generic.mustache
+++ b/modules/openapi-generator/src/main/resources/php-nextgen/model_generic.mustache
@@ -214,7 +214,7 @@ class {{classname}} {{#parentSchema}}extends {{{parent}}}{{/parentSchema}}{{^par
      *
      * @return string[]
      */
-    public function {{getter}}AllowableValues()
+    public static function {{getter}}AllowableValues()
     {
         return [
 {{#discriminator}}
diff --git a/samples/client/echo_api/php-nextgen-streaming/src/Model/DefaultValue.php b/samples/client/echo_api/php-nextgen-streaming/src/Model/DefaultValue.php
index f91870e9b6c..5a0c2710396 100644
--- a/samples/client/echo_api/php-nextgen-streaming/src/Model/DefaultValue.php
+++ b/samples/client/echo_api/php-nextgen-streaming/src/Model/DefaultValue.php
@@ -280,7 +280,7 @@ class DefaultValue implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getArrayStringEnumDefaultAllowableValues()
+    public static function getArrayStringEnumDefaultAllowableValues()
     {
         return [
             self::ARRAY_STRING_ENUM_DEFAULT_SUCCESS,
diff --git a/samples/client/echo_api/php-nextgen-streaming/src/Model/Pet.php b/samples/client/echo_api/php-nextgen-streaming/src/Model/Pet.php
index 949d976b215..815710545bb 100644
--- a/samples/client/echo_api/php-nextgen-streaming/src/Model/Pet.php
+++ b/samples/client/echo_api/php-nextgen-streaming/src/Model/Pet.php
@@ -267,7 +267,7 @@ class Pet implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getStatusAllowableValues()
+    public static function getStatusAllowableValues()
     {
         return [
             self::STATUS_AVAILABLE,
diff --git a/samples/client/echo_api/php-nextgen-streaming/src/Model/Query.php b/samples/client/echo_api/php-nextgen-streaming/src/Model/Query.php
index 574bc5380b8..fcaeac69a6a 100644
--- a/samples/client/echo_api/php-nextgen-streaming/src/Model/Query.php
+++ b/samples/client/echo_api/php-nextgen-streaming/src/Model/Query.php
@@ -243,7 +243,7 @@ class Query implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getOutcomesAllowableValues()
+    public static function getOutcomesAllowableValues()
     {
         return [
             self::OUTCOMES_SUCCESS,
diff --git a/samples/client/echo_api/php-nextgen/src/Model/DefaultValue.php b/samples/client/echo_api/php-nextgen/src/Model/DefaultValue.php
index f91870e9b6c..5a0c2710396 100644
--- a/samples/client/echo_api/php-nextgen/src/Model/DefaultValue.php
+++ b/samples/client/echo_api/php-nextgen/src/Model/DefaultValue.php
@@ -280,7 +280,7 @@ class DefaultValue implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getArrayStringEnumDefaultAllowableValues()
+    public static function getArrayStringEnumDefaultAllowableValues()
     {
         return [
             self::ARRAY_STRING_ENUM_DEFAULT_SUCCESS,
diff --git a/samples/client/echo_api/php-nextgen/src/Model/Pet.php b/samples/client/echo_api/php-nextgen/src/Model/Pet.php
index 949d976b215..815710545bb 100644
--- a/samples/client/echo_api/php-nextgen/src/Model/Pet.php
+++ b/samples/client/echo_api/php-nextgen/src/Model/Pet.php
@@ -267,7 +267,7 @@ class Pet implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getStatusAllowableValues()
+    public static function getStatusAllowableValues()
     {
         return [
             self::STATUS_AVAILABLE,
diff --git a/samples/client/echo_api/php-nextgen/src/Model/Query.php b/samples/client/echo_api/php-nextgen/src/Model/Query.php
index 574bc5380b8..fcaeac69a6a 100644
--- a/samples/client/echo_api/php-nextgen/src/Model/Query.php
+++ b/samples/client/echo_api/php-nextgen/src/Model/Query.php
@@ -243,7 +243,7 @@ class Query implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getOutcomesAllowableValues()
+    public static function getOutcomesAllowableValues()
     {
         return [
             self::OUTCOMES_SUCCESS,
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/EnumArrays.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/EnumArrays.php
index 7312068fbdc..ed10ecb249c 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/EnumArrays.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/EnumArrays.php
@@ -243,7 +243,7 @@ class EnumArrays implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getJustSymbolAllowableValues()
+    public static function getJustSymbolAllowableValues()
     {
         return [
             self::JUST_SYMBOL_GREATER_THAN_OR_EQUAL_TO,
@@ -256,7 +256,7 @@ class EnumArrays implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getArrayEnumAllowableValues()
+    public static function getArrayEnumAllowableValues()
     {
         return [
             self::ARRAY_ENUM_FISH,
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/EnumTest.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/EnumTest.php
index 9a0f0fc2c68..a5a2b2c4c23 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/EnumTest.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/EnumTest.php
@@ -285,7 +285,7 @@ class EnumTest implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getEnumStringAllowableValues()
+    public static function getEnumStringAllowableValues()
     {
         return [
             self::ENUM_STRING_UPPER,
@@ -299,7 +299,7 @@ class EnumTest implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getEnumStringRequiredAllowableValues()
+    public static function getEnumStringRequiredAllowableValues()
     {
         return [
             self::ENUM_STRING_REQUIRED_UPPER,
@@ -313,7 +313,7 @@ class EnumTest implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getEnumIntegerAllowableValues()
+    public static function getEnumIntegerAllowableValues()
     {
         return [
             self::ENUM_INTEGER_NUMBER_1,
@@ -326,7 +326,7 @@ class EnumTest implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getEnumNumberAllowableValues()
+    public static function getEnumNumberAllowableValues()
     {
         return [
             self::ENUM_NUMBER_NUMBER_1_DOT_1,
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/MapTest.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/MapTest.php
index 6d5a0d17ae6..0c80f2d4071 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/MapTest.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/MapTest.php
@@ -253,7 +253,7 @@ class MapTest implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getMapOfEnumStringAllowableValues()
+    public static function getMapOfEnumStringAllowableValues()
     {
         return [
             self::MAP_OF_ENUM_STRING_UPPER,
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/Order.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/Order.php
index 87f1b9139e4..190d899b3f7 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/Order.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/Order.php
@@ -266,7 +266,7 @@ class Order implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getStatusAllowableValues()
+    public static function getStatusAllowableValues()
     {
         return [
             self::STATUS_PLACED,
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/ParentWithNullable.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/ParentWithNullable.php
index d3b7a383750..b971b2d1427 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/ParentWithNullable.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/ParentWithNullable.php
@@ -240,7 +240,7 @@ class ParentWithNullable implements ModelInterface, ArrayAccess, JsonSerializabl
      *
      * @return string[]
      */
-    public function getTypeAllowableValues()
+    public static function getTypeAllowableValues()
     {
         return [
             self::TYPE_CHILD_WITH_NULLABLE,
diff --git a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/Pet.php b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/Pet.php
index a00b4141e74..5d56fe5a944 100644
--- a/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/Pet.php
+++ b/samples/client/petstore/php-nextgen/OpenAPIClient-php/src/Model/Pet.php
@@ -266,7 +266,7 @@ class Pet implements ModelInterface, ArrayAccess, JsonSerializable
      *
      * @return string[]
      */
-    public function getStatusAllowableValues()
+    public static function getStatusAllowableValues()
     {
         return [
             self::STATUS_AVAILABLE,