diff --git a/C/atomic.c b/C/atomic.c
index 14744d434..cfe1c099c 100644
--- a/C/atomic.c
+++ b/C/atomic.c
@@ -442,6 +442,7 @@ restart_aux:
 static Int atom_codes(USES_REGS1) {
   Term t1;
   t1 = Deref(ARG1);
+  LOCAL_Error_TYPE = 0;
 restart_aux:
   if (IsAtomTerm(t1)) {
     Term tf = Yap_AtomToListOfCodes(t1 PASS_REGS);
diff --git a/C/heapgc.c b/C/heapgc.c
index 6159b19d6..8cec0ac7f 100644
--- a/C/heapgc.c
+++ b/C/heapgc.c
@@ -467,7 +467,7 @@ push_registers(Int num_regs, yamop *nextop USES_REGS)
 	  (
 	  (*curslot < (CELL)LOCAL_GlobalBase &&
 	   *curslot > (CELL)HR))) {
-	*curslot++ = TermNil;
+	*curslot++ = TermFreeTerm;
       }
 	TrailTerm(TR++) = (CELL)curslot++;
       }