diff --git a/compiler/forget/src/HIR/HIR.ts b/compiler/forget/src/HIR/HIR.ts
index 075e6db1bf..95d5e7f6ae 100644
--- a/compiler/forget/src/HIR/HIR.ts
+++ b/compiler/forget/src/HIR/HIR.ts
@@ -284,7 +284,6 @@ export type Primitive = {
 
 /*
  * Range in which an identifier is mutable. Start and End refer to Instruction.id.
- * TODO(gsn): Type Instruction.id better and use it here.
  *
  * Start is inclusive, End is exclusive (ie, end is the "first" instruction for which
  * the value is not mutable).