diff --git a/compiler/rustc_smir/src/stable_mir/ty.rs b/compiler/rustc_smir/src/stable_mir/ty.rs
index 1ccb30343ed..ba120be04b2 100644
--- a/compiler/rustc_smir/src/stable_mir/ty.rs
+++ b/compiler/rustc_smir/src/stable_mir/ty.rs
@@ -91,9 +91,7 @@ pub struct GenericArgs(pub Vec<GenericArgKind>);
 
 #[derive(Clone, Debug)]
 pub enum GenericArgKind {
-    // FIXME add proper region
     Lifetime(Region),
     Type(Ty),
-    // FIXME add proper const
     Const(Const),
 }