diff --git a/samples/schema/petstore/mysql/.openapi-generator/VERSION b/samples/schema/petstore/mysql/.openapi-generator/VERSION
index 875e2d486ac..afa63656064 100644
--- a/samples/schema/petstore/mysql/.openapi-generator/VERSION
+++ b/samples/schema/petstore/mysql/.openapi-generator/VERSION
@@ -1 +1 @@
-3.4.0-SNAPSHOT
\ No newline at end of file
+4.0.0-SNAPSHOT
\ No newline at end of file
diff --git a/samples/server/petstore/php-lumen/lib/routes/web.php b/samples/server/petstore/php-lumen/lib/routes/web.php
index 5be001e3841..bb7417bc266 100644
--- a/samples/server/petstore/php-lumen/lib/routes/web.php
+++ b/samples/server/petstore/php-lumen/lib/routes/web.php
@@ -49,9 +49,8 @@ $router->get('/v2/fake', 'FakeApi@testEnumParameters');
  * delete testGroupParameters
  * Summary: Fake endpoint to test group parameters (optional)
  * Notes: Fake endpoint to test group parameters (optional)
-
  */
-$app->delete('/v2/fake', 'FakeApi@testGroupParameters');
+$router->delete('/v2/fake', 'FakeApi@testGroupParameters');
 /**
  * put testBodyWithFileSchema
  * Summary: 
diff --git a/samples/server/petstore/springboot-virtualan/.openapi-generator/VERSION b/samples/server/petstore/springboot-virtualan/.openapi-generator/VERSION
index 875e2d486ac..afa63656064 100644
--- a/samples/server/petstore/springboot-virtualan/.openapi-generator/VERSION
+++ b/samples/server/petstore/springboot-virtualan/.openapi-generator/VERSION
@@ -1 +1 @@
-3.4.0-SNAPSHOT
\ No newline at end of file
+4.0.0-SNAPSHOT
\ No newline at end of file
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/AnotherFakeApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/AnotherFakeApi.java
index cc233303be3..9898cb4c7dc 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/AnotherFakeApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/AnotherFakeApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.4.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (4.0.0-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeApi.java
index 5d28a9eca17..504063a3245 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.4.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (4.0.0-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeClassnameTestApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeClassnameTestApi.java
index db17d405edd..d1af25787b1 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeClassnameTestApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/FakeClassnameTestApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.4.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (4.0.0-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/PetApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/PetApi.java
index c7c470ed0da..30220a4aba8 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/PetApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/PetApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.4.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (4.0.0-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/StoreApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/StoreApi.java
index 082739d5caf..a71a9bdde1b 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/StoreApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/StoreApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.4.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (4.0.0-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */
diff --git a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/UserApi.java b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/UserApi.java
index c8bde7a680e..caf8a91e5e6 100644
--- a/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/UserApi.java
+++ b/samples/server/petstore/springboot-virtualan/src/main/java/org/openapitools/virtualan/api/UserApi.java
@@ -1,5 +1,5 @@
 /**
- * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (3.4.0-SNAPSHOT).
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech) (4.0.0-SNAPSHOT).
  * https://openapi-generator.tech
  * Do not edit the class manually.
  */