diff --git a/ghc-lib-parser.cabal b/ghc-lib-parser.cabal
--- a/ghc-lib-parser.cabal
+++ b/ghc-lib-parser.cabal
@@ -1,7 +1,7 @@
 cabal-version: >=1.22
 build-type: Simple
 name: ghc-lib-parser
-version: 8.8.3.20200224
+version: 8.8.3.20200412
 license: BSD3
 license-file: LICENSE
 category: Development
@@ -77,7 +77,7 @@
         build-depends: Win32
     build-depends:
         ghc-prim > 0.2 && < 0.6,
-        base >= 4.11 && < 4.14,
+        base >= 4.11 && < 4.15,
         containers >= 0.5 && < 0.7,
         bytestring >= 0.9 && < 0.11,
         binary == 0.8.*,
@@ -125,6 +125,7 @@
         UnboxedTuples
         UndecidableInstances
     c-sources:
+        libraries/ghc-heap/cbits/HeapPrim.cmm
         compiler/cbits/genSym.c
         compiler/parser/cutils.c
     hs-source-dirs:
diff --git a/ghc-lib/stage0/compiler/build/Parser.hs b/ghc-lib/stage0/compiler/build/Parser.hs
--- a/ghc-lib/stage0/compiler/build/Parser.hs
+++ b/ghc-lib/stage0/compiler/build/Parser.hs
@@ -12533,7 +12533,7 @@
 
 
 {-# LINE 19 "<built-in>" #-}
-{-# LINE 1 "/var/folders/kc/bjk2hzwx6bv07jz_s80wjh7w0000gn/T/ghc30110_0/ghc_2.h" #-}
+{-# LINE 1 "/var/folders/kc/bjk2hzwx6bv07jz_s80wjh7w0000gn/T/ghc3107_0/ghc_2.h" #-}
 
 
 
diff --git a/libraries/ghc-heap/GHC/Exts/Heap/Closures.hs b/libraries/ghc-heap/GHC/Exts/Heap/Closures.hs
--- a/libraries/ghc-heap/GHC/Exts/Heap/Closures.hs
+++ b/libraries/ghc-heap/GHC/Exts/Heap/Closures.hs
@@ -44,13 +44,10 @@
 ------------------------------------------------------------------------
 -- Boxes
 
-aToWord# :: Any -> Word#
-aToWord# _ = 0##
-
-
-reallyUnsafePtrEqualityUpToTag# :: Any -> Any -> Int#
-reallyUnsafePtrEqualityUpToTag# _ _ = 0#
+foreign import prim "aToWordzh" aToWord# :: Any -> Word#
 
+foreign import prim "reallyUnsafePtrEqualityUpToTag"
+    reallyUnsafePtrEqualityUpToTag# :: Any -> Any -> Int#
 
 -- | An arbitrary Haskell value in a safe Box. The point is that even
 -- unevaluated thunks can safely be moved around inside the Box, and when
diff --git a/libraries/ghc-heap/cbits/HeapPrim.cmm b/libraries/ghc-heap/cbits/HeapPrim.cmm
new file mode 100644
--- /dev/null
+++ b/libraries/ghc-heap/cbits/HeapPrim.cmm
@@ -0,0 +1,13 @@
+#include "Cmm.h"
+
+aToWordzh (P_ clos)
+{
+    return (clos);
+}
+
+reallyUnsafePtrEqualityUpToTag (W_ clos1, W_  clos2)
+{
+    clos1 = UNTAG(clos1);
+    clos2 = UNTAG(clos2);
+    return (clos1 == clos2);
+}