diff --git a/docs/TODO b/docs/TODO
index f55a665c4d..914b9a312d 100644
--- a/docs/TODO
+++ b/docs/TODO
@@ -22,6 +22,7 @@
  1.3 struct lifreq
  1.4 alt-svc sharing
  1.5 get rid of PATH_MAX
+ 1.6 thread-safe sharing
  1.8 CURLOPT_RESOLVE for any port number
  1.9 Cache negative name resolves
  1.10 auto-detect proxy
@@ -247,6 +248,13 @@
  there we need libssh2 to properly tell us when we pass in a too small buffer
  and its current API (as of libssh2 1.2.7) does not.
 
+1.6 thread-safe sharing
+
+ Using the share interface users can share some data between easy handles but
+ several of the sharing options are documented as as not safe and supported to
+ share between multiple concurrent threads. Fixing this would enable more
+ users to share data in more powerful ways.
+
 1.8 CURLOPT_RESOLVE for any port number
 
  This option allows applications to set a replacement IP address for a given