diff --git a/src/librustc_typeck/diagnostics.rs b/src/librustc_typeck/diagnostics.rs
index 9a536a5e0a13..c2ce16b02566 100644
--- a/src/librustc_typeck/diagnostics.rs
+++ b/src/librustc_typeck/diagnostics.rs
@@ -3214,7 +3214,7 @@ register_diagnostics! {
     E0090,
     E0103, // @GuillaumeGomez: I was unable to get this error, try your best!
     E0104,
-    E0118,
+    E0118, // implementation for undefined or unsutable type
 //  E0123,
 //  E0127,
 //  E0129,