diff --git a/dma-helpers.c b/dma-helpers.c
index 712ed89..0c57648 100644
--- a/dma-helpers.c
+++ b/dma-helpers.c
@@ -12,7 +12,10 @@
 
 void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint)
 {
-    qsg->sg = qemu_malloc(alloc_hint * sizeof(ScatterGatherEntry));
+    if (alloc_hint > 0)
+       qsg->sg = qemu_malloc(alloc_hint * sizeof(ScatterGatherEntry));
+    else
+       qsg->sg = NULL;
     qsg->nsg = 0;
     qsg->nalloc = alloc_hint;
     qsg->size = 0;