diff --git a/GHC/Exts/Heap/Closures.hs b/GHC/Exts/Heap/Closures.hs
--- a/GHC/Exts/Heap/Closures.hs
+++ b/GHC/Exts/Heap/Closures.hs
@@ -6,6 +6,9 @@
 {-# LANGUAGE UnliftedFFITypes #-}
 {-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE DeriveTraversable #-}
+-- Late cost centres introduce a thunk in the asBox function, which leads to
+-- an additional wrapper being added to any value placed inside a box.
+{-# OPTIONS_GHC -fno-prof-late  #-}
 
 module GHC.Exts.Heap.Closures (
     -- * Closures
diff --git a/ghc-heap.cabal b/ghc-heap.cabal
--- a/ghc-heap.cabal
+++ b/ghc-heap.cabal
@@ -1,6 +1,6 @@
 cabal-version:  3.0
 name:           ghc-heap
-version:        9.10.3
+version:        9.12.1
 license:        BSD-3-Clause
 license-file:   LICENSE
 maintainer:     libraries@haskell.org
@@ -23,12 +23,12 @@
   default-language: Haskell2010
 
   build-depends:    base             >= 4.9.0 && < 5.0
-                  , ghc-prim         > 0.2 && < 0.13
+                  , ghc-prim         > 0.2 && < 0.14
                   , rts              == 1.0.*
                   , containers       >= 0.6.2.1 && < 0.8
 
   if impl(ghc >= 9.9)
-    build-depends:  ghc-internal     >= 9.900 && < 9.1003.99999
+    build-depends:  ghc-internal     >= 9.900 && < 9.1201.99999
 
   ghc-options:      -Wall
   if !os(ghcjs)