diff --git a/modules/openapi-generator/src/main/resources/php-symfony/api_controller.mustache b/modules/openapi-generator/src/main/resources/php-symfony/api_controller.mustache
index 3ab32095ec5..b0f2efbc93f 100644
--- a/modules/openapi-generator/src/main/resources/php-symfony/api_controller.mustache
+++ b/modules/openapi-generator/src/main/resources/php-symfony/api_controller.mustache
@@ -178,7 +178,7 @@ class {{controllerName}} extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
diff --git a/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/PetController.php b/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/PetController.php
index b9644ba4178..3eda55dfa00 100644
--- a/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/PetController.php
+++ b/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/PetController.php
@@ -121,7 +121,7 @@ class PetController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -207,7 +207,7 @@ class PetController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -294,7 +294,7 @@ class PetController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -378,7 +378,7 @@ class PetController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -462,7 +462,7 @@ class PetController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -555,7 +555,7 @@ class PetController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -649,7 +649,7 @@ class PetController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -742,7 +742,7 @@ class PetController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
diff --git a/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/StoreController.php b/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/StoreController.php
index f9a4c9b6540..96bf511cf18 100644
--- a/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/StoreController.php
+++ b/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/StoreController.php
@@ -109,7 +109,7 @@ class StoreController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -179,7 +179,7 @@ class StoreController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -260,7 +260,7 @@ class StoreController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -345,7 +345,7 @@ class StoreController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
diff --git a/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/UserController.php b/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/UserController.php
index f240d652c01..c2c454fc131 100644
--- a/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/UserController.php
+++ b/samples/server/petstore/php-symfony/SymfonyBundle-php/Controller/UserController.php
@@ -115,7 +115,7 @@ class UserController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -199,7 +199,7 @@ class UserController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -283,7 +283,7 @@ class UserController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -359,7 +359,7 @@ class UserController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -438,7 +438,7 @@ class UserController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -524,7 +524,7 @@ class UserController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -589,7 +589,7 @@ class UserController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,
@@ -682,7 +682,7 @@ class UserController extends Controller
             }
 
             return new Response(
-                $result?$this->serialize($result, $responseFormat):'',
+                $result !== null ?$this->serialize($result, $responseFormat):'',
                 $responseCode,
                 array_merge(
                     $responseHeaders,