diff --git a/src/EmbedIO/Files/FileModule.cs b/src/EmbedIO/Files/FileModule.cs
index 124270d63..23d1199de 100644
--- a/src/EmbedIO/Files/FileModule.cs
+++ b/src/EmbedIO/Files/FileModule.cs
@@ -540,6 +540,7 @@ await source.CopyToAsync(compressor, WebServer.StreamCopyBufferSize, context.Can
                     }
 
                     content = memoryStream.ToArray();
+                    responseContentLength = content.Length;
                 }
 
                 cacheItem.SetContent(compressionMethod, content);