diff --git a/lib/buffer.c b/lib/buffer.c
index b689549..ee93101 100644
--- a/lib/buffer.c
+++ b/lib/buffer.c
@@ -148,7 +148,7 @@
 {
   struct buffer_data *d;
 
-  d = XMALLOC(MTYPE_BUFFER_DATA, offsetof(struct buffer_data, data[b->size]));
+  d = XMALLOC(MTYPE_BUFFER_DATA, offsetof(struct buffer_data, data) + b->size);
   d->cp = d->sp = 0;
   d->next = NULL;