diff --git a/disk/part.c b/disk/part.c
index d73625c..9400a97 100644
--- a/disk/part.c
+++ b/disk/part.c
@@ -548,6 +548,8 @@ int get_device_and_partition(const char *ifname, const char *dev_part_str,
 			goto cleanup;
 		}
 
+		(*dev_desc)->log2blksz = LOG2((*dev_desc)->blksz);
+
 		info->start = 0;
 		info->size = (*dev_desc)->lba;
 		info->blksz = (*dev_desc)->blksz;
@@ -631,6 +633,8 @@ int get_device_and_partition(const char *ifname, const char *dev_part_str,
 		goto cleanup;
 	}
 
+	(*dev_desc)->log2blksz = LOG2((*dev_desc)->blksz);
+
 	ret = part;
 	goto cleanup;