diff --git a/source/oar.cpp b/source/oar.cpp
index 74cb933..c3d2e9e 100755
--- a/source/oar.cpp
+++ b/source/oar.cpp
@@ -260,8 +260,7 @@ struct walker final : public file_walker {
 
 export namespace oar {
 	struct archive : public fs {
-		archive(fs * backing_fs, path const & archive_path) {
-			this->backing_fs = backing_fs;
+		archive(fs & backing_fs, path const & archive_path) : backing_fs{backing_fs} {
 			this->archive_path = archive_path;
 		}
 
@@ -269,7 +268,7 @@ export namespace oar {
 		 * See [fs::walk_files].
 		 */
 		void walk_files(path const & target_path, closure<void(file_walker &)> const & then) override {
-			this->backing_fs->read_file(this->archive_path, [&](file_reader & archive_reader) {
+			this->backing_fs.read_file(this->archive_path, [&](file_reader & archive_reader) {
 				entry archive_entry{&archive_reader};
 
 				if (archive_entry.find(entry_kind::directory, target_path) != entry::find_result::ok) return;
@@ -284,9 +283,7 @@ export namespace oar {
 		 * See [fs::read_file].
 		 */
 		void read_file(path const & file_path, closure<void(file_reader &)> const & then) override {
-			if ((this->backing_fs == nullptr) || (this->archive_path.byte_size() == 0)) return;
-
-			this->backing_fs->read_file(this->archive_path, [&](file_reader & archive_reader) {
+			this->backing_fs.read_file(this->archive_path, [&](file_reader & archive_reader) {
 				entry archive_entry {&archive_reader};
 
 				if (archive_entry.find(entry_kind::file, file_path) != entry::find_result::ok) return;
@@ -296,7 +293,7 @@ export namespace oar {
 		}
 
 		private:
-		fs * backing_fs;
+		fs & backing_fs;
 
 		path archive_path;
 	};