M README.md → README.md

@@ -61,9 +61,10 @@ * [Obtain a stack trace when tint2 crashes](https://gitlab.com/o9000/tint2/wikis/Debug)
 
 # Known issues
 
-  * Graphic glitches on Intel graphics cards can be avoided by changing the acceleration method to UXA ([issue 595](https://gitlab.com/o9000/tint2/issues/595))
-  * Window managers that do not follow exactly the EWMH specification might not interact well with tint2 (known issues for [awesome](https://gitlab.com/o9000/tint2/issues/385), [bspwm](https://gitlab.com/o9000/tint2/issues/524). [openbox-multihead](https://gitlab.com/o9000/tint2/issues/456))
-  * Full transparency requires a compositor such as Compton (if not provided already by the window manager, as in Compiz/Unity, KDE or XFCE)
+  * Graphical glitches on Intel graphics cards can be avoided by changing the acceleration method to UXA ([issue 595](https://gitlab.com/o9000/tint2/issues/595))
+  * Window managers that do not follow exactly the EWMH specification might not interact well with tint2 ([issue 627](https://gitlab.com/o9000/tint2/issues/627)).
+  * Full transparency requires a compositor such as Compton (if not provided already by the window manager, as in Compiz/Unity, KDE or XFCE).
+  * As of version 16.0, tint2 requires a C11 compiler (such as GCC version 4.9 or newer).
 
 # How can I help out?