diff --git a/modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache b/modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache
index 6e2a4aa2583..812ac789ae5 100644
--- a/modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp/ApiClient.mustache
@@ -245,6 +245,7 @@ namespace {{packageName}}.Client
             var request = PrepareRequest(
                 path, method, queryParams, postBody, headerParams, formParams, fileParams,
                 pathParams, contentType);
+            RestClient.UserAgent = Configuration.UserAgent;
             InterceptRequest(request);
             var response = await RestClient.Execute{{^netStandard}}TaskAsync{{/netStandard}}(request);
             InterceptResponse(request, response);
diff --git a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Client/ApiClient.cs b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Client/ApiClient.cs
index 216469e1c8b..973dc3ec597 100644
--- a/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Client/ApiClient.cs
+++ b/samples/client/petstore/csharp/OpenAPIClient/src/Org.OpenAPITools/Client/ApiClient.cs
@@ -202,6 +202,7 @@ namespace Org.OpenAPITools.Client
             var request = PrepareRequest(
                 path, method, queryParams, postBody, headerParams, formParams, fileParams,
                 pathParams, contentType);
+            RestClient.UserAgent = Configuration.UserAgent;
             InterceptRequest(request);
             var response = await RestClient.ExecuteTaskAsync(request);
             InterceptResponse(request, response);