diff --git a/modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache b/modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache
index 76f82b67dbe..9b9a281b625 100644
--- a/modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache
+++ b/modules/openapi-generator/src/main/resources/php/HeaderSelector.mustache
@@ -72,8 +72,8 @@ class HeaderSelector
     {
         if (count($accept) === 0 || (count($accept) === 1 && $accept[0] === '')) {
             return null;
-        } elseif (preg_grep("/application\/json/i", $accept)) {
-            return 'application/json';
+        } elseif ($jsonAccept = preg_grep('~(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$~', $accept)) {
+            return implode(',', $jsonAccept);
         } else {
             return implode(',', $accept);
         }
diff --git a/samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php b/samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
index b8b298ec95c..af9dda69434 100644
--- a/samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
+++ b/samples/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
@@ -82,8 +82,8 @@ class HeaderSelector
     {
         if (count($accept) === 0 || (count($accept) === 1 && $accept[0] === '')) {
             return null;
-        } elseif (preg_grep("/application\/json/i", $accept)) {
-            return 'application/json';
+        } elseif ($jsonAccept = preg_grep('~(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$~', $accept)) {
+            return implode(',', $jsonAccept);
         } else {
             return implode(',', $accept);
         }
diff --git a/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php b/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
index b8b298ec95c..af9dda69434 100644
--- a/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
+++ b/samples/openapi3/client/petstore/php/OpenAPIClient-php/lib/HeaderSelector.php
@@ -82,8 +82,8 @@ class HeaderSelector
     {
         if (count($accept) === 0 || (count($accept) === 1 && $accept[0] === '')) {
             return null;
-        } elseif (preg_grep("/application\/json/i", $accept)) {
-            return 'application/json';
+        } elseif ($jsonAccept = preg_grep('~(?i)^(application/json|[^;/ \t]+/[^;/ \t]+[+]json)[ \t]*(;.*)?$~', $accept)) {
+            return implode(',', $jsonAccept);
         } else {
             return implode(',', $accept);
         }