diff --git a/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache b/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache
index e54c30d3e0e6..f0df804e264c 100644
--- a/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/Java/libraries/vertx/ApiClient.mustache
@@ -680,54 +680,54 @@ public class ApiClient{{#jsr310}} extends JavaTimeFormatter{{/jsr310}} {
 
         private final Map<String, Authentication> authentications = new LinkedHashMap<>();{{#authMethods}}{{#isBasic}}{{#isBasicBasic}}
 
-        public void add{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(String username, String password) {
+        public void add{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(String username, String password) {
             HttpBasicAuth auth = new HttpBasicAuth();
             auth.setUsername(username);
             auth.setPassword(password);
             authentications.put("{{name}}", auth);
         }{{/isBasicBasic}}{{#isBasicBearer}}
 
-        public void add{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(String bearerToken) {
+        public void add{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(String bearerToken) {
            HttpBearerAuth auth = new
            HttpBearerAuth("{{scheme}}");
            auth.setBearerToken(bearerToken);
            authentications.put("{{name}}", auth);
         }{{/isBasicBearer}}{{/isBasic}}{{#isApiKey}}
 
-        public void add{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(String apikey, String apiKeyPrefix) {
+        public void add{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(String apikey, String apiKeyPrefix) {
            ApiKeyAuth auth = new ApiKeyAuth({{#isKeyInHeader}}"header"{{/isKeyInHeader}}{{#isKeyInQuery}}"query"{{/isKeyInQuery}}{{#isKeyInCookie}}"cookie"{{/isKeyInCookie}},"{{keyParamName}}");
            auth.setApiKey(apikey);
            auth.setApiKeyPrefix(apiKeyPrefix);
            authentications.put("{{name}}", auth);
         }{{/isApiKey}}{{#isOAuth}}
 
-        public void add{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(String accessToken) {
+        public void add{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(String accessToken) {
            OAuth auth = new OAuth();
            auth.setAccessToken(accessToken);
            authentications.put("{{name}}", auth);
         }{{/isOAuth}}{{/authMethods}}{{#authMethods}}{{#isBasic}}{{#isBasicBasic}}
 
-        public static AuthInfo for{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}(String username, String password) {
+        public static AuthInfo for{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}(String username, String password) {
             AuthInfo authInfo = new AuthInfo();
-            authInfo.add{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(username, password);
+            authInfo.add{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(username, password);
             return authInfo;
         }{{/isBasicBasic}}{{#isBasicBearer}}
 
-        public static AuthInfo for{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(String bearerToken) {
+        public static AuthInfo for{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(String bearerToken) {
             AuthInfo authInfo = new AuthInfo();
-            authInfo.add{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(bearerToken);
+            authInfo.add{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(bearerToken);
             return authInfo;
         }{{/isBasicBearer}}{{/isBasic}}{{#isApiKey}}
 
-        public static AuthInfo for{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(String apikey, String apiKeyPrefix) {
+        public static AuthInfo for{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(String apikey, String apiKeyPrefix) {
             AuthInfo authInfo = new AuthInfo();
-            authInfo.add{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(apikey, apiKeyPrefix);
+            authInfo.add{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(apikey, apiKeyPrefix);
             return authInfo;
         }{{/isApiKey}}{{#isOAuth}}
 
-        public static AuthInfo for{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(String accessToken) {
+        public static AuthInfo for{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(String accessToken) {
             AuthInfo authInfo = new AuthInfo();
-            authInfo.add{{#lambda.titlecase}}{{#lambda.camelcase}}{{name}}{{/lambda.camelcase}}{{/lambda.titlecase}}Authentication(accessToken);
+            authInfo.add{{#lambda.pascalcase}}{{name}}{{/lambda.pascalcase}}Authentication(accessToken);
             return authInfo;
         }{{/isOAuth}}{{/authMethods}}
     }