diff --git a/modules/swagger-codegen/src/main/resources/JavaSpring/apiDelegate.mustache b/modules/swagger-codegen/src/main/resources/JavaSpring/apiDelegate.mustache
index 482cdb1b2fb..cde9a5d81a6 100644
--- a/modules/swagger-codegen/src/main/resources/JavaSpring/apiDelegate.mustache
+++ b/modules/swagger-codegen/src/main/resources/JavaSpring/apiDelegate.mustache
@@ -61,7 +61,7 @@ public interface {{classname}}Delegate {
     /**
      * @see {{classname}}#{{operationId}}
      */
-    {{#jdk8}}default {{/jdk8}}{{#responseWrapper}}{{.}}<{{/responseWrapper}}ResponseEntity<{{>returnTypes}}>{{#responseWrapper}}>{{/responseWrapper}} {{operationId}}({{#allParams}}{{^isFile}}{{{dataType}}}{{/isFile}}{{#isFile}}MultipartFile{{/isFile}} {{paramName}}{{#hasMore}},
+    {{#jdk8}}default {{/jdk8}}{{#responseWrapper}}{{.}}<{{/responseWrapper}}ResponseEntity<{{>returnTypes}}>{{#responseWrapper}}>{{/responseWrapper}} {{operationId}}({{#allParams}}{{^isFile}} {{>optionalDataType}} {{/isFile}}{{#isFile}}MultipartFile{{/isFile}} {{paramName}}{{#hasMore}},
         {{/hasMore}}{{/allParams}}){{^jdk8}};{{/jdk8}}{{#jdk8}} {
         if(getObjectMapper().isPresent() && getAcceptHeader().isPresent()) {
         {{#examples}}