diff --git a/test/Microsoft.AspNetCore.StaticFiles.Tests/CacheHeaderTests.cs b/test/Microsoft.AspNetCore.StaticFiles.Tests/CacheHeaderTests.cs
index 6f9d8c9015..dc8d643330 100644
--- a/test/Microsoft.AspNetCore.StaticFiles.Tests/CacheHeaderTests.cs
+++ b/test/Microsoft.AspNetCore.StaticFiles.Tests/CacheHeaderTests.cs
@@ -340,7 +340,7 @@ namespace Microsoft.AspNetCore.StaticFiles
             {
                 HttpResponseMessage res2 = await server
                     .CreateRequest("/SubFolder/extra.xml")
-                    .AddHeader("If-Modified-Since", DateTimeOffset.Now.ToString(format))
+                    .AddHeader("If-Modified-Since", DateTimeOffset.UtcNow.ToString(format))
                     .SendAsync(method.Method);
 
                 Assert.Equal(HttpStatusCode.NotModified, res2.StatusCode);