diff --git a/crypto777/iguana_OS.c b/crypto777/iguana_OS.c
index e78716f2d..a4e58b932 100755
--- a/crypto777/iguana_OS.c
+++ b/crypto777/iguana_OS.c
@@ -406,6 +406,8 @@ int64_t iguana_memallocated(struct OS_memspace *mem)
 void *iguana_memalloc(struct OS_memspace *mem,long size,int32_t clearflag)
 {
     int32_t modval; void *ptr = 0;
+    if ( mem->ptr == 0 )
+        return(0);
     //printf("iguana_memalloc.%s size.%ld used.%llu of %llu, numptrs.%d avail.%d %lld\n",mem->name,size,(long long)mem->used,(long long)mem->totalsize,mem->numptrs,mem->availptrs,(long long)iguana_memallocated(mem));
     //if ( mem->threadsafe != 0 )
     //    portable_mutex_lock(&mem->mutex);
diff --git a/iguana/iguana_ramchain.c b/iguana/iguana_ramchain.c
index b57b5d8e8..5aa918a01 100755
--- a/iguana/iguana_ramchain.c
+++ b/iguana/iguana_ramchain.c
@@ -1297,10 +1297,9 @@ int32_t iguana_ramchain_extras(struct iguana_info *coin,struct iguana_ramchain *
             if ( (ramchain->hashmem= hashmem) != 0 )
                 iguana_memreset(hashmem);
             else printf("alloc ramchain->A %ld\n",sizeof(struct iguana_account) * ramchain->H.data->numpkinds);
-            ramchain->A = (hashmem != 0) ? iguana_memalloc(hashmem,sizeof(struct iguana_account) * ramchain->H.data->numpkinds,1) : mycalloc('p',ramchain->H.data->numpkinds,sizeof(struct iguana_account));
-            ramchain->Uextras = (hashmem != 0) ? iguana_memalloc(hashmem,sizeof(*ramchain->Uextras) * ramchain->H.data->numunspents,1) : mycalloc('p',ramchain->H.data->numunspents,sizeof(*ramchain->Uextras));
-        }
-        else err = iguana_volatilesmap(coin,ramchain);
+            ramchain->A = (hashmem != 0 && hashmem->ptr != 0) ? iguana_memalloc(hashmem,sizeof(struct iguana_account) * ramchain->H.data->numpkinds,1) : mycalloc('p',ramchain->H.data->numpkinds,sizeof(struct iguana_account));
+            ramchain->Uextras = (hashmem != 0 && hashmem->ptr != 0) ? iguana_memalloc(hashmem,sizeof(*ramchain->Uextras) * ramchain->H.data->numunspents,1) : mycalloc('p',ramchain->H.data->numunspents,sizeof(*ramchain->Uextras));
+        } else err = iguana_volatilesmap(coin,ramchain);
     }
     return(err);
 }