diff --git a/include/sys/zio.h b/include/sys/zio.h
index 278b6e0868..4916d87249 100644
--- a/include/sys/zio.h
+++ b/include/sys/zio.h
@@ -525,6 +525,7 @@ extern void *zio_buf_alloc(size_t size);
 extern void zio_buf_free(void *buf, size_t size);
 extern void *zio_data_buf_alloc(size_t size);
 extern void zio_data_buf_free(void *buf, size_t size);
+extern void *zio_buf_alloc_flags(size_t size, int flags);
 
 extern void zio_resubmit_stage_async(void *);
 
diff --git a/module/zfs/vdev_queue.c b/module/zfs/vdev_queue.c
index 4a4544f29e..0c62a6fa3c 100644
--- a/module/zfs/vdev_queue.c
+++ b/module/zfs/vdev_queue.c
@@ -502,6 +502,7 @@ vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio)
 	boolean_t stretch = B_FALSE;
 	avl_tree_t *t = vdev_queue_type_tree(vq, zio->io_type);
 	enum zio_flag flags = zio->io_flags & ZIO_FLAG_AGG_INHERIT;
+	void *buf;
 
 	if (zio->io_flags & ZIO_FLAG_DONT_AGGREGATE)
 		return (NULL);
@@ -608,8 +609,12 @@ vdev_queue_aggregate(vdev_queue_t *vq, zio_t *zio)
 	size = IO_SPAN(first, last);
 	ASSERT3U(size, <=, zfs_vdev_aggregation_limit);
 
+	buf = zio_buf_alloc_flags(size, KM_NOSLEEP);
+	if (buf == NULL)
+		return (NULL);
+
 	aio = zio_vdev_delegated_io(first->io_vd, first->io_offset,
-	    zio_buf_alloc(size), size, first->io_type, zio->io_priority,
+	    buf, size, first->io_type, zio->io_priority,
 	    flags | ZIO_FLAG_DONT_CACHE | ZIO_FLAG_DONT_QUEUE,
 	    vdev_queue_agg_io_done, NULL);
 	aio->io_timestamp = first->io_timestamp;
diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index c378742eda..794439bbe7 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -248,6 +248,20 @@ zio_data_buf_alloc(size_t size)
 	return (kmem_cache_alloc(zio_data_buf_cache[c], KM_PUSHPAGE));
 }
 
+/*
+ * Use zio_buf_alloc_flags when specific allocation flags are needed.  e.g.
+ * passing KM_NOSLEEP when it is acceptable for an allocation to fail.
+ */
+void *
+zio_buf_alloc_flags(size_t size, int flags)
+{
+	size_t c = (size - 1) >> SPA_MINBLOCKSHIFT;
+
+	VERIFY3U(c, <, SPA_MAXBLOCKSIZE >> SPA_MINBLOCKSHIFT);
+
+	return (kmem_cache_alloc(zio_buf_cache[c], flags));
+}
+
 void
 zio_buf_free(void *buf, size_t size)
 {
@@ -3458,6 +3472,7 @@ zbookmark_is_before(const dnode_phys_t *dnp, const zbookmark_phys_t *zb1,
 EXPORT_SYMBOL(zio_type_name);
 EXPORT_SYMBOL(zio_buf_alloc);
 EXPORT_SYMBOL(zio_data_buf_alloc);
+EXPORT_SYMBOL(zio_buf_alloc_flags);
 EXPORT_SYMBOL(zio_buf_free);
 EXPORT_SYMBOL(zio_data_buf_free);