diff --git a/source/coral/files.cpp b/source/coral/files.cpp
index 96536ba..8a59106 100644
--- a/source/coral/files.cpp
+++ b/source/coral/files.cpp
@@ -137,7 +137,7 @@ export namespace coral {
 		/**
 		 * Returns the [io_rules] that this file system interface abides by.
 		 */
-		virtual io_rules rules() = 0;
+		virtual io_rules rules() const = 0;
 
 		/**
 		 * Attempts to write the file in the file system located at `file_path` relative, calling