diff --git a/lib/blob/blobstore.c b/lib/blob/blobstore.c
index dc5a20ed2..ebbf8d012 100644
--- a/lib/blob/blobstore.c
+++ b/lib/blob/blobstore.c
@@ -1381,7 +1381,7 @@ _spdk_blob_load_cpl_extents_cpl(spdk_bs_sequence_t *seq, void *cb_arg, int bserr
 				_spdk_blob_load_final(ctx, -ENOMEM);
 				return;
 			}
-			memset(tmp + blob->active.cluster_array_size, 0,
+			memset(tmp + sizeof(*blob->active.clusters) * blob->active.cluster_array_size, 0,
 			       sizeof(*blob->active.clusters) * (blob->active.num_clusters - blob->active.cluster_array_size));
 			blob->active.clusters = tmp;
 			blob->active.cluster_array_size = blob->active.num_clusters;