diff --git a/C/grow.c b/C/grow.c
index e7216286e..72ae89a93 100644
--- a/C/grow.c
+++ b/C/grow.c
@@ -1307,6 +1307,10 @@ static int do_growtrail(long size, int contiguous_only, int in_parser, tr_fr_ptr
   UInt start_growth_time = Yap_cputime(), growth_time;
   int gc_verbose = Yap_is_gc_verbose();
 
+#if USE_SYSTEM_MALLOC
+  if (contiguous_only)
+    return FALSE;
+#endif
   /* at least 64K for trail */
   if (size < 64*1024)
     size = 64*1024;
diff --git a/C/heapgc.c b/C/heapgc.c
index 56c688aff..f038d1ee6 100644
--- a/C/heapgc.c
+++ b/C/heapgc.c
@@ -149,18 +149,12 @@ static rb_red_blk_node *db_root, *db_nil;
 static void
 gc_growtrail(int committed)
 {
-#if USE_SYSTEM_MALLOC
-  TR = OldTR;
-  save_machine_regs();
-  longjmp(Yap_gc_restore, 2);
-#else
   if (!Yap_growtrail(64 * 1024L, TRUE)) {
+    TR = OldTR;
     /* could not find more trail */
     save_machine_regs();
     longjmp(Yap_gc_restore, 2);
   }
-#endif
-  
 }
 
 inline static void
@@ -1600,8 +1594,9 @@ mark_trail(tr_fr_ptr trail_ptr, tr_fr_ptr trail_base, CELL *gc_H, choiceptr gc_B
 	  tr_fr_ptr nsTR = (tr_fr_ptr)cont_top0;
           CELL *cptr = (CELL *)trail_cell;
 
-	  if ((ADDR)nsTR > Yap_TrailTop-1024)
-	    Yap_growtrail(64 * 1024L, TRUE);
+	  if ((ADDR)nsTR > Yap_TrailTop-1024) {
+	    gc_growtrail(TRUE);
+	  }
 	  TrailTerm(nsTR) = (CELL)NULL;
 	  TrailTerm(nsTR+1) = *hp;
 	  TrailTerm(nsTR+2) = trail_cell;
diff --git a/C/scanner.c b/C/scanner.c
index fba18fa2f..5f3d75c27 100644
--- a/C/scanner.c
+++ b/C/scanner.c
@@ -128,13 +128,6 @@ typedef struct scanner_extra_alloc {
   void *filler;
 } ScannerExtraBlock;
 
-/* Problem: we use realloc so we cannot guarantee beforehand pointers will shift or not */
-#if USE_SYSTEM_MALLOC
-#define EXPAND_TRAIL FALSE
-#else
-#define EXPAND_TRAIL TRUE
-#endif
-
 static char *
 AllocScannerMemory(unsigned int size)
 {
@@ -156,7 +149,7 @@ AllocScannerMemory(unsigned int size)
  
     if (size > alloc_size)
       alloc_size = size;
-    if(!EXPAND_TRAIL || !Yap_growtrail(alloc_size, TRUE)) {
+    if(!Yap_growtrail(alloc_size, TRUE)) {
       struct scanner_extra_alloc *ptr;
 
       if (!(ptr = (struct scanner_extra_alloc *)malloc(size+sizeof(ScannerExtraBlock)))) {
diff --git a/C/write.c b/C/write.c
index 24772dd3e..e42f5f367 100644
--- a/C/write.c
+++ b/C/write.c
@@ -453,12 +453,16 @@ writeTerm(Term t, int p, int depth, int rinfixarg, struct write_globs *wglb)
 #ifdef USE_GMP
       case (CELL)FunctorBigInt:
 	{
-	  char *s = (char *)TR;
 	  MP_INT *big = Yap_BigIntOfTerm(t);
-	  while (s+2+mpz_sizeinbase(big, 10) > (char *)Yap_TrailTop) {
-	    Yap_growtrail(2+mpz_sizeinbase(big, 10), TRUE);
-	    big = Yap_BigIntOfTerm(t);
+	  char *s = (char *)TR;
+	  if (s+2+mpz_sizeinbase(big, 10) >= Yap_TrailTop) {
+	    s = H;
+	    if (s+2+mpz_sizeinbase(big, 10) >= ASP) {
+	      return;
+	    }
 	  }
+	  if (!s)
+	    return;
 	  if (mpz_sgn(big) < 0) {
 	    if (lastw == symbol)
 	      wrputc(' ', wglb->writech);