diff --git a/calyx-utils/src/position.rs b/calyx-utils/src/position.rs
index 869271006..1ff3d5aef 100644
--- a/calyx-utils/src/position.rs
+++ b/calyx-utils/src/position.rs
@@ -33,6 +33,11 @@ struct PosData {
 }
 
 /// Source position information for a Calyx program.
+///
+/// Note: This is rather large because of [`boxcar::Vec`] so it may be worth
+/// putting those behind a [`Box`] in the future. Granted the PositionTable is
+/// only ever constructed once statically so the extra indirection probably
+/// doesn't actually buy us anything.
 struct PositionTable {
     /// The source files of the program
     files: boxcar::Vec<File>,