diff --git a/ghc/includes/Stg.h b/ghc/includes/Stg.h
index 0ae31a0d944584ec40d3296af1d6f1d908b904b5..cf0f6f5dc763f12e7cdb225be6aaf9fa65c7ef79 100644
--- a/ghc/includes/Stg.h
+++ b/ghc/includes/Stg.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Stg.h,v 1.22 2000/01/13 14:34:01 hwloidl Exp $
+ * $Id: Stg.h,v 1.23 2000/03/13 10:53:55 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -156,9 +156,6 @@ void _stgAssert (char *, unsigned int);
 /* GNU mp library */
 #include "gmp.h"
 
-/* Wired-in Prelude identifiers */
-#include "Prelude.h"
-
 /* Storage Manager */
 #include "StgStorage.h"
 
diff --git a/ghc/rts/Main.c b/ghc/rts/Main.c
index 49abe0323ddcb83fe1eebb39ce7dcb8b3d140b48..154eaa4bbbead77993594752380f0b181b02b847 100644
--- a/ghc/rts/Main.c
+++ b/ghc/rts/Main.c
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Main.c,v 1.16 2000/01/14 13:38:54 simonmar Exp $
+ * $Id: Main.c,v 1.17 2000/03/13 10:53:55 simonmar Exp $
  *
  * (c) The GHC Team 1998-1999
  *
@@ -14,6 +14,7 @@
 #include "SchedAPI.h"
 #include "RtsFlags.h"
 #include "RtsUtils.h"
+#include "Prelude.h"
 
 #ifdef DEBUG
 # include "Printer.h"   /* for printing        */
diff --git a/ghc/rts/Prelude.h b/ghc/rts/Prelude.h
new file mode 100644
index 0000000000000000000000000000000000000000..82123195b8f1358c5e66f5c7e8a54db411501423
--- /dev/null
+++ b/ghc/rts/Prelude.h
@@ -0,0 +1,103 @@
+/* -----------------------------------------------------------------------------
+ * $Id: Prelude.h,v 1.1 2000/03/13 10:53:56 simonmar Exp $
+ *
+ * (c) The GHC Team, 1998-1999
+ *
+ * Prelude identifiers that we sometimes need to refer to in the RTS.
+ *
+ * ---------------------------------------------------------------------------*/
+
+#ifndef PRELUDE_H
+#define PRELUDE_H
+
+#ifdef COMPILING_RTS
+
+#ifdef COMPILER
+extern DLL_IMPORT const StgClosure PrelBase_Z91Z93_static_closure;
+extern DLL_IMPORT const StgClosure PrelBase_Z40Z41_static_closure;
+extern DLL_IMPORT const StgClosure PrelBase_True_static_closure;
+extern DLL_IMPORT const StgClosure PrelBase_False_static_closure;
+extern DLL_IMPORT const StgClosure PrelPack_unpackCString_closure;
+extern DLL_IMPORT const StgClosure PrelException_stackOverflow_closure;
+extern DLL_IMPORT const StgClosure PrelException_heapOverflow_closure;
+extern DLL_IMPORT const StgClosure PrelException_PutFullMVar_static_closure;
+extern DLL_IMPORT const StgClosure PrelException_NonTermination_static_closure;
+extern const StgClosure PrelMain_mainIO_closure;
+
+extern DLL_IMPORT const StgInfoTable PrelBase_Czh_static_info;
+extern DLL_IMPORT const StgInfoTable PrelBase_Izh_static_info;
+extern DLL_IMPORT const StgInfoTable PrelFloat_Fzh_static_info;
+extern DLL_IMPORT const StgInfoTable PrelFloat_Dzh_static_info;
+extern DLL_IMPORT const StgInfoTable PrelAddr_Azh_static_info;
+extern DLL_IMPORT const StgInfoTable PrelAddr_Wzh_static_info;
+extern DLL_IMPORT const StgInfoTable PrelBase_Czh_con_info;
+extern DLL_IMPORT const StgInfoTable PrelBase_Izh_con_info;
+extern DLL_IMPORT const StgInfoTable PrelFloat_Fzh_con_info;
+extern DLL_IMPORT const StgInfoTable PrelFloat_Dzh_con_info;
+extern DLL_IMPORT const StgInfoTable PrelAddr_Azh_con_info;
+extern DLL_IMPORT const StgInfoTable PrelAddr_Wzh_con_info;
+extern DLL_IMPORT const StgInfoTable PrelAddr_I64zh_con_info;
+extern DLL_IMPORT const StgInfoTable PrelAddr_W64zh_con_info;
+extern DLL_IMPORT const StgInfoTable PrelStable_StablePtr_static_info;
+extern DLL_IMPORT const StgInfoTable PrelStable_StablePtr_con_info;
+
+/* Define canonical names so we can abstract away from the actual
+ * module these names are defined in.
+ */
+
+#define Nil_closure            PrelBase_ZMZN_static_closure
+#define Unit_closure           PrelBase_Z0T_static_closure
+#define True_closure           PrelBase_True_static_closure
+#define False_closure          PrelBase_False_static_closure
+#define stackOverflow_closure  PrelException_stackOverflow_closure
+#define heapOverflow_closure   PrelException_heapOverflow_closure
+#define PutFullMVar_closure    PrelException_PutFullMVar_static_closure
+#define NonTermination_closure PrelException_NonTermination_static_closure
+#define Czh_static_info        PrelBase_Czh_static_info
+#define Izh_static_info        PrelBase_Izh_static_info
+#define Fzh_static_info        PrelFloat_Fzh_static_info
+#define Dzh_static_info        PrelFloat_Dzh_static_info
+#define Azh_static_info        PrelAddr_Azh_static_info
+#define Wzh_static_info        PrelAddr_Wzh_static_info
+#define Czh_con_info           PrelBase_Czh_con_info
+#define Izh_con_info           PrelBase_Izh_con_info
+#define Fzh_con_info           PrelFloat_Fzh_con_info
+#define Dzh_con_info           PrelFloat_Dzh_con_info
+#define Azh_con_info           PrelAddr_Azh_con_info
+#define Wzh_con_info           PrelAddr_Wzh_con_info
+#define W64zh_con_info         PrelAddr_W64zh_con_info
+#define I64zh_con_info         PrelAddr_I64zh_con_info
+#define StablePtr_static_info  PrelStable_StablePtr_static_info
+#define StablePtr_con_info     PrelStable_StablePtr_con_info
+
+#define mainIO_closure         PrelMain_mainIO_closure
+#define unpackCString_closure  PrelPack_unpackCString_closure
+
+#else /* INTERPRETER, I guess */
+
+extern const StgInfoTable Czh_con_info;
+extern const StgInfoTable Izh_con_info;
+extern const StgInfoTable I64zh_con_info;
+extern const StgInfoTable Fzh_con_info;
+extern const StgInfoTable Dzh_con_info;
+extern const StgInfoTable Azh_con_info;
+extern const StgInfoTable Wzh_con_info;
+extern const StgInfoTable StablePtr_con_info;
+
+extern const StgInfoTable Czh_static_info;
+extern const StgInfoTable Izh_static_info;
+extern const StgInfoTable I64zh_static_info;
+extern const StgInfoTable Fzh_static_info;
+extern const StgInfoTable Dzh_static_info;
+extern const StgInfoTable Azh_static_info;
+extern const StgInfoTable Wzh_static_info;
+extern const StgInfoTable StablePtr_static_info;
+
+#define W64zh_con_info        I64zh_con_info
+#define W64zh_static_info     I64zh_con_info
+
+#endif
+
+#endif /* COMPILING_RTS */
+
+#endif /* PRELUDE_H */
diff --git a/ghc/rts/PrimOps.hc b/ghc/rts/PrimOps.hc
index 709947a8289ef1d9860418abe8188b1efb4e4f6b..ff672a02d7e429f32d322ef7677c0862bfb34ef3 100644
--- a/ghc/rts/PrimOps.hc
+++ b/ghc/rts/PrimOps.hc
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: PrimOps.hc,v 1.43 2000/02/28 13:59:43 simonmar Exp $
+ * $Id: PrimOps.hc,v 1.44 2000/03/13 10:53:56 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -19,6 +19,7 @@
 #include "StablePriv.h"
 #include "HeapStackCheck.h"
 #include "StgRun.h"
+#include "Prelude.h"
 
 /* ** temporary **
 
@@ -903,7 +904,8 @@ FN_(putMVarzh_fast)
 #endif
 
   if (info == &FULL_MVAR_info) {
-    barf("putMVar#: MVar already full");
+    R1.cl = (StgClosure *)&PutFullMVar_closure;
+    JMP_(raisezh_fast);
   }
   
   mvar->value = R2.cl;
diff --git a/ghc/rts/RtsAPI.c b/ghc/rts/RtsAPI.c
index fb4df6ced2fda128dbdd8470e133c8e36d231e47..0009fb69bdede45e0c41e431c3b967b487cd9f59 100644
--- a/ghc/rts/RtsAPI.c
+++ b/ghc/rts/RtsAPI.c
@@ -1,5 +1,5 @@
 /* ----------------------------------------------------------------------------
- * $Id: RtsAPI.c,v 1.10 1999/11/02 15:05:59 simonmar Exp $
+ * $Id: RtsAPI.c,v 1.11 2000/03/13 10:53:56 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -13,6 +13,7 @@
 #include "SchedAPI.h"
 #include "RtsFlags.h"
 #include "RtsUtils.h"
+#include "Prelude.h"
 
 /* ----------------------------------------------------------------------------
    Building Haskell objects from C datatypes.
diff --git a/ghc/rts/Schedule.c b/ghc/rts/Schedule.c
index fa7ce4136404c7ac1b470fddec52b9b2acb10b2d..a425fc203195b99b937890d4a4b78b431e83b6b9 100644
--- a/ghc/rts/Schedule.c
+++ b/ghc/rts/Schedule.c
@@ -1,5 +1,5 @@
 /* ---------------------------------------------------------------------------
- * $Id: Schedule.c,v 1.50 2000/03/13 09:57:16 simonmar Exp $
+ * $Id: Schedule.c,v 1.51 2000/03/13 10:53:56 simonmar Exp $
  *
  * (c) The GHC Team, 1998-2000
  *
@@ -72,6 +72,7 @@
 #include "Sanity.h"
 #include "Stats.h"
 #include "Sparks.h"
+#include "Prelude.h"
 #if defined(GRAN) || defined(PAR)
 # include "GranSimRts.h"
 # include "GranSim.h"
diff --git a/ghc/rts/StgMiscClosures.hc b/ghc/rts/StgMiscClosures.hc
index c904f9db6264f0989da2626235f9fa9731efa86a..5e966c39099c6a5fad5ace4d5aa11a7be4f9c2a2 100644
--- a/ghc/rts/StgMiscClosures.hc
+++ b/ghc/rts/StgMiscClosures.hc
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: StgMiscClosures.hc,v 1.36 2000/03/01 16:57:57 sewardj Exp $
+ * $Id: StgMiscClosures.hc,v 1.37 2000/03/13 10:53:55 simonmar Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -15,6 +15,7 @@
 #include "Storage.h"
 #include "StoragePriv.h"
 #include "ProfRts.h"
+#include "Prelude.h"
 #include "SMP.h"
 #if defined(GRAN) || defined(PAR)
 # include "GranSimRts.h"      /* for DumpRawGranEvent */