diff --git a/C/exo.c b/C/exo.c
index 4d3a68fa8..afb6dedd5 100644
--- a/C/exo.c
+++ b/C/exo.c
@@ -421,7 +421,7 @@ p_exodb_get_space( USES_REGS1 )
   Yap_ClauseSpace += required;
   /* cool, it's our turn to do the conversion */
   mcl->ClFlags = MegaMask|ExoMask;
-  mcl->ClSize = required-sizeof(MegaClause);
+  mcl->ClSize = required;
   mcl->ClPred = ap;
   mcl->ClItemSize = arity*sizeof(CELL);
   mcl->ClNext = NULL;
diff --git a/C/qlyr.c b/C/qlyr.c
index 5c473b718..00417535d 100755
--- a/C/qlyr.c
+++ b/C/qlyr.c
@@ -849,6 +849,7 @@ read_clauses(IOSTREAM *stream, PredEntry *pp, UInt nclauses, UInt flags) {
   } else if (pp->PredFlags & MegaClausePredFlag) {
     CACHE_REGS
     char *base = (void *)read_uint(stream);
+    UInt mask = read_uint(stream);
     UInt size = read_uint(stream);
     MegaClause *cl = (MegaClause *)Yap_AlwaysAllocCodeSpace(size);
 
@@ -857,12 +858,20 @@ read_clauses(IOSTREAM *stream, PredEntry *pp, UInt nclauses, UInt flags) {
     }
     LOCAL_HDiff = (char *)cl-base;
     read_bytes(stream, cl, size);
+    cl->ClFlags = mask;
     pp->cs.p_code.FirstClause =
       pp->cs.p_code.LastClause =
       cl->ClCode;
     pp->PredFlags |= MegaClausePredFlag;
     /* enter index mode */
-    pp->OpcodeOfPred = INDEX_OPCODE;
+    if (mask & ExoMask) { 
+      struct index_t **icl = (struct index_t **)(cl->ClCode); 
+      pp->OpcodeOfPred = Yap_opcode(_enter_exo);
+      icl[0] = NULL;
+      icl[1] = NULL;
+    } else {
+      pp->OpcodeOfPred = INDEX_OPCODE;
+    }
     pp->CodeOfPred = pp->cs.p_code.TrueCodeOfPred = (yamop *)(&(pp->OpcodeOfPred)); 
     /* This must be set for restoremegaclause */
     pp->cs.p_code.NOfClauses = nclauses;
diff --git a/C/qlyw.c b/C/qlyw.c
index 0bde3d2e6..cb5187921 100755
--- a/C/qlyw.c
+++ b/C/qlyw.c
@@ -649,6 +649,7 @@ save_clauses(IOSTREAM *stream, PredEntry *pp) {
     UInt size = cl->ClSize;
 
     CHECK(save_uint(stream, (UInt)cl));
+    CHECK(save_uint(stream, (UInt)(cl->ClFlags)));
     CHECK(save_uint(stream, size));
     CHECK(save_bytes(stream, cl, size));
   } else if (pp->PredFlags & DynamicPredFlag) {
diff --git a/H/rheap.h b/H/rheap.h
index 5c04ef8f2..663b443bf 100644
--- a/H/rheap.h
+++ b/H/rheap.h
@@ -588,10 +588,21 @@ RestoreMegaClause(MegaClause *cl USES_REGS)
   }
   max = (yamop *)((CODEADDR)cl+cl->ClSize);
 
-  for (ptr = cl->ClCode; ptr < max; ) {
-    nextptr = (yamop *)((char *)ptr + cl->ClItemSize);
-    restore_opcodes(ptr, nextptr PASS_REGS);
-    ptr = nextptr;
+  if (cl->ClFlags & ExoMask) {
+    CELL *base = (CELL *)((ADDR)cl->ClCode+2*sizeof(struct index_t *));
+    CELL *end = (CELL*)max, *ptr;
+
+    for (ptr = base; ptr < end; ptr++) {
+      Term t = *ptr;
+      if (IsAtomTerm(t)) *ptr = AtomTermAdjust(t);
+      /* don't handle other complex terms just yet, ints are ok  */
+    }
+  } else {
+    for (ptr = cl->ClCode; ptr < max; ) {
+      nextptr = (yamop *)((char *)ptr + cl->ClItemSize);
+      restore_opcodes(ptr, nextptr PASS_REGS);
+      ptr = nextptr;
+    }
   }
 }