diff --git a/TASKS.md b/TASKS.md
index bc4b5e0..7806e93 100644
--- a/TASKS.md
+++ b/TASKS.md
@@ -50,7 +50,7 @@ Progress truth. Top to bottom, one at a time. A task is ticked only after its co
 ## 11. Background blur
 
 - [x] T19 macOS and Windows: `Blurred` or `Transparent` or `Opaque` from settings, applied live.
-- [ ] T20 Wayland: `ext_background_effect_v1` on the window's surface.
+- [x] T20 Wayland: `ext_background_effect_v1` on the window's surface.
 - [ ] T21 X11: `_KDE_NET_WM_BLUR_BEHIND_REGION` on the window.
 
 ## 12. Menus and shortcuts
diff --git a/tasks/reviews.md b/tasks/reviews.md
index 796ce8f..ded7b68 100644
--- a/tasks/reviews.md
+++ b/tasks/reviews.md
@@ -99,3 +99,7 @@ Each task gets at most three codex rounds. Each round: the commit, the verdict,
 ## T19
 
 - Round 1, c98bbad: PASS.
+
+## T20
+
+- Round 1, 6523632 and 107069b: PASS. 6523632 fixed a test the first Linux run caught: on Linux a program that ignores SIGHUP reads EIO when its pty closes, so GNU cat exits 1 where macOS gives EOF.