diff --git a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/api.mustache b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/api.mustache
index e1d5220101c..00b28c20aab 100644
--- a/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/Java/libraries/retrofit2/api.mustache
@@ -14,6 +14,7 @@ import retrofit2.Call;
 import retrofit2.http.*;
 
 import okhttp3.RequestBody;
+import okhttp3.ResponseBody;
 
 {{#imports}}import {{import}};
 {{/imports}}
@@ -55,7 +56,7 @@ public interface {{classname}} {
   {{/prioritizedContentTypes}}
   {{/formParams}}  
   @{{httpMethod}}("{{{path}}}")
-  {{^doNotUseRx}}Observable{{/doNotUseRx}}{{#doNotUseRx}}Call{{/doNotUseRx}}<{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Object{{/returnType}}> {{operationId}}({{^allParams}});{{/allParams}}
+  {{^doNotUseRx}}Observable{{/doNotUseRx}}{{#doNotUseRx}}Call{{/doNotUseRx}}<{{#isResponseFile}}ResponseBody{{/isResponseFile}}{{^isResponseFile}}{{#returnType}}{{{returnType}}}{{/returnType}}{{^returnType}}Object{{/returnType}}{{/isResponseFile}}> {{operationId}}({{^allParams}});{{/allParams}}
     {{#allParams}}{{>libraries/retrofit2/queryParams}}{{>libraries/retrofit2/pathParams}}{{>libraries/retrofit2/headerParams}}{{>libraries/retrofit2/bodyParams}}{{>libraries/retrofit2/formParams}}{{#hasMore}}, {{/hasMore}}{{^hasMore}}
   );{{/hasMore}}{{/allParams}}