diff --git a/src/core/file_sys/disk_archive.h b/src/core/file_sys/disk_archive.h
index 0e875d1945..fd6983ed1d 100644
--- a/src/core/file_sys/disk_archive.h
+++ b/src/core/file_sys/disk_archive.h
@@ -46,7 +46,7 @@ protected:
 
 class DiskDirectory : public DirectoryBackend {
 public:
-    DiskDirectory(const std::string& path);
+    explicit DiskDirectory(const std::string& path);
 
     ~DiskDirectory() override {
         Close();