diff --git a/inbuild/supervisor-module/Chapter 4/Project Bundle Manager.w b/inbuild/supervisor-module/Chapter 4/Project Bundle Manager.w
index c4156c034..4b3f1771c 100644
--- a/inbuild/supervisor-module/Chapter 4/Project Bundle Manager.w	
+++ b/inbuild/supervisor-module/Chapter 4/Project Bundle Manager.w	
@@ -221,7 +221,7 @@ inbuild_copy *ProjectBundleManager::claim_folder_as_copy(pathname *P) {
 		if (Platform::is_folder_separator(Str::get_last_char(entry)) == FALSE) {
 			TEMPORARY_TEXT(ext)
 			Filenames::write_extension(ext, Filenames::from_text(entry));
-			if (Str::eq_insensitive(ext, I".html") == FALSE) == FALSE) {
+			if (Str::eq_insensitive(ext, I".html") == FALSE) {
 				TEMPORARY_TEXT(error_text)
 				WRITE_TO(error_text,
 					"the 'Index' subdirectory of the project directory '%S' contains a "