diff --git a/compiler/rustc_middle/src/query/plumbing.rs b/compiler/rustc_middle/src/query/plumbing.rs
index 57da5b39ba7..20ba1b27c0e 100644
--- a/compiler/rustc_middle/src/query/plumbing.rs
+++ b/compiler/rustc_middle/src/query/plumbing.rs
@@ -319,7 +319,7 @@ pub fn provided_to_erased<'tcx>(
 
                 pub type Storage<'tcx> = <$($K)* as keys::Key>::Cache<Erase<$V>>;
 
-                // Ensure that keys grow no larger than 72 bytes by accident.
+                // Ensure that keys grow no larger than 80 bytes by accident.
                 // Increase this limit if necessary, but do try to keep the size low if possible
                 #[cfg(target_pointer_width = "64")]
                 const _: () = {