diff --git a/OpenAPIService.Test/OpenAPIServiceShould.cs b/OpenAPIService.Test/OpenAPIServiceShould.cs
index 0f98f1ff3..58d8f419a 100644
--- a/OpenAPIService.Test/OpenAPIServiceShould.cs
+++ b/OpenAPIService.Test/OpenAPIServiceShould.cs
@@ -8,6 +8,7 @@
 using System.Linq;
 using System.Text;
 using System.Text.Json;
+using System.Threading.Tasks;
 using Microsoft.OpenApi;
 using Microsoft.OpenApi.Extensions;
 using Microsoft.OpenApi.Models;
@@ -584,7 +585,7 @@ public void SetByRefPostfixForRefOperationIds()
         }
 
         [Fact]
-        public void GetOpenApiTreeNode()
+        public async Task GetOpenApiTreeNodeAsync()
         {
             // Arrange
             var sources = new ConcurrentDictionary<string, OpenApiDocument>();
@@ -593,7 +594,7 @@ public void GetOpenApiTreeNode()
             // Act
             var rootNode = _openApiService.CreateOpenApiUrlTreeNode(sources);
             using MemoryStream stream = new();
-            ConvertOpenApiUrlTreeNodeToJson(rootNode, stream);
+            await ConvertOpenApiUrlTreeNodeToJsonAsync(rootNode, stream);
 
             // Assert
             var jsonPayload = Encoding.ASCII.GetString(stream.ToArray());
@@ -720,10 +721,10 @@ public void ConvertOpenApiUrlTreeNodeToJsonRendersExternalDocs()
             Assert.Contains("\"children\":[{\"segment\":\"{user-id}\",\"labels\":[{\"name\":\"mock\",\"methods\":[{\"name\":\"Get\",\"documentationUrl\":\"https://docs.microsoft.com/foobar\"}", output);
         }
 
-        private void ConvertOpenApiUrlTreeNodeToJson(OpenApiUrlTreeNode node, Stream stream)
+        private async Task ConvertOpenApiUrlTreeNodeToJsonAsync(OpenApiUrlTreeNode node, Stream stream)
         {
             Assert.NotNull(node);
-            _openApiService.ConvertOpenApiUrlTreeNodeToJson(node, stream);
+            await _openApiService.ConvertOpenApiUrlTreeNodeToJsonAsync(node, stream);
             Assert.True(stream.Length > 0);
         }
     }
diff --git a/OpenAPIService/Interfaces/IOpenApiService.cs b/OpenAPIService/Interfaces/IOpenApiService.cs
index d6df9a39a..c9baea41d 100644
--- a/OpenAPIService/Interfaces/IOpenApiService.cs
+++ b/OpenAPIService/Interfaces/IOpenApiService.cs
@@ -25,7 +25,7 @@ Func<OpenApiOperation, bool> CreatePredicate(string operationIds, string tags, s
 
         OpenApiUrlTreeNode CreateOpenApiUrlTreeNode(ConcurrentDictionary<string, OpenApiDocument> sources);
 
-        void ConvertOpenApiUrlTreeNodeToJson(OpenApiUrlTreeNode rootNode, Stream stream);
+        Task ConvertOpenApiUrlTreeNodeToJsonAsync(OpenApiUrlTreeNode rootNode, Stream stream);
 
         OpenApiDocument ApplyStyle(OpenApiStyle style, OpenApiDocument subsetOpenApiDocument, bool includeRequestBody = false, bool singularizeOperationIds = false);
 
diff --git a/OpenAPIService/OpenApiService.cs b/OpenAPIService/OpenApiService.cs
index 0cc59bb4a..fe84c0401 100644
--- a/OpenAPIService/OpenApiService.cs
+++ b/OpenAPIService/OpenApiService.cs
@@ -394,11 +394,11 @@ private OpenApiOperation[] GetOpenApiOperations(OpenApiUrlTreeNode rootNode, str
         /// </summary>
         /// <param name="rootNode">The target <see cref="OpenApiUrlTreeNode"/> root node.</param>
         /// <param name="stream">The destination for writing the JSON text to.</param>
-        public void ConvertOpenApiUrlTreeNodeToJson(OpenApiUrlTreeNode rootNode, Stream stream)
+        public async Task ConvertOpenApiUrlTreeNodeToJsonAsync(OpenApiUrlTreeNode rootNode, Stream stream)
         {
             using Utf8JsonWriter writer = new Utf8JsonWriter(stream);
             ConvertOpenApiUrlTreeNodeToJson(writer, rootNode);
-            writer.FlushAsync();
+            await writer.FlushAsync();
         }
 
         /// <summary>