diff --git a/src/config/error.rs b/src/config/error.rs
index 8132abf..77ce4e7 100644
--- a/src/config/error.rs
+++ b/src/config/error.rs
@@ -1,17 +1,33 @@
 //! Config parsing error
-
 use super::*;
+use std::{
+    io,
+};
 
 #[derive(Debug)]
 pub enum Error {
-    
+    IO(io::Error),
+
+    Unknown,
 }
 
-impl std::error::Error for Error{}
+impl std::error::Error for Error
+{
+    fn source(&self) -> Option<&(dyn std::error::Error + 'static)>
+    {
+	Some(match &self {
+	    Self::IO(io) => io,
+	    _ => return None,
+	})
+    }
+}
 impl std::fmt::Display for Error
 {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result
     {
-	todo!()
+	match self {
+	    Self::IO(io) => write!(f, "i/o error: {}", io),
+	    Self::Unknown => write!(f, "unknown error")
+	}
     }
 }