diff --git a/http/vibe/http/server.d b/http/vibe/http/server.d
index cf64c99e21..7f4efec3c2 100644
--- a/http/vibe/http/server.d
+++ b/http/vibe/http/server.d
@@ -224,8 +224,12 @@ version (Have_diet_ng)
 
 	@dietTraits
 	private struct DefaultFilters {
+		import diet.html : HTMLOutputStyle;
 		import std.string : splitLines;
 
+		version (VibeOutputCompactHTML) enum HTMLOutputStyle htmlOutputStyle = HTMLOutputStyle.compact;
+		else enum HTMLOutputStyle htmlOutputStyle = HTMLOutputStyle.pretty;
+
 		static string filterCss(I)(I text, size_t indent = 0)
 		{
 			auto lines = splitLines(text);