diff --git a/src/unwrap.c b/src/unwrap.c
index 56185c5..3018618 100644
--- a/src/unwrap.c
+++ b/src/unwrap.c
@@ -86,6 +86,8 @@ static int unwrap(
 	const struct ec3_tag_info *target_tag_info
 		= ec3_image_ioctx_get_tag_info_by_id(image, target_tag_ident);
 	size_t tag_length = target_tag_info->tag_total_length;
+	size_t total_clusters;
+	ec3_tag_ioctx_get_nr_clusters(tag, &total_clusters);
 
 	printf("reading %zu bytes from tag %s...\n", tag_length, ident_str);
 
@@ -93,7 +95,7 @@ static int unwrap(
 
 	int ret = 0;
 	FILE *outp = fopen("data.bin", "wb");
-	for (size_t i = 0;; i++) {
+	for (size_t i = 0; i < total_clusters; i++) {
 		size_t nr_read = 0;
 		enum ec3_status status
 			= ec3_tag_ioctx_read_cluster(tag, i, buf, &nr_read);
@@ -108,10 +110,6 @@ static int unwrap(
 
 		printf("read %zu bytes from cluster %zu\n", nr_read, i);
 		fwrite(buf, 1, nr_read, outp);
-
-		if (nr_read < c_info->img_cluster_size) {
-			break;
-		}
 	}
 
 	free(buf);