diff --git a/doc/design/v6.mdwn b/doc/design/v6.mdwn
index 3a3bce7aa7..aaec302a8d 100644
--- a/doc/design/v6.mdwn
+++ b/doc/design/v6.mdwn
@@ -46,7 +46,7 @@ Possible reasons to make changes:
   problems.
 
 * The hash directories, and also the per-key directories
-  can slow down using a repository on a non-SSD disk.
+  can slow down using a repository on a disk (both SSD and spinning).
   
   <https://github.com/datalad/datalad/issues/32>