diff -Nru qtwayland-opensource-src-5.15.2/debian/changelog qtwayland-opensource-src-5.15.2/debian/changelog
--- qtwayland-opensource-src-5.15.2/debian/changelog	2021-07-10 10:22:01.000000000 +0000
+++ qtwayland-opensource-src-5.15.2/debian/changelog	2021-08-16 12:46:20.000000000 +0000
@@ -1,3 +1,10 @@
+qtwayland-opensource-src (5.15.2-4) unstable; urgency=medium
+
+  * Backport upstream patch to fix build with GCC 11 (closes: #984312).
+  * Update debian/watch: use version=4, and track only 5.15.x releases.
+
+ -- Dmitry Shachnev <mitya57@debian.org>  Mon, 16 Aug 2021 15:46:20 +0300
+
 qtwayland-opensource-src (5.15.2-3) unstable; urgency=medium
 
   * Backport upstream patch to fix accented and dead key combinations
diff -Nru qtwayland-opensource-src-5.15.2/debian/patches/gcc_11.diff qtwayland-opensource-src-5.15.2/debian/patches/gcc_11.diff
--- qtwayland-opensource-src-5.15.2/debian/patches/gcc_11.diff	1970-01-01 00:00:00.000000000 +0000
+++ qtwayland-opensource-src-5.15.2/debian/patches/gcc_11.diff	2021-08-16 12:46:20.000000000 +0000
@@ -0,0 +1,14 @@
+Description: build fixes for GCC 11
+Origin: upstream, https://code.qt.io/cgit/qt/qtwayland.git/commit/?id=1aa6ec2c778504d9
+Last-Update: 2021-08-10
+
+--- a/tests/auto/client/shared/corecompositor.cpp
++++ b/tests/auto/client/shared/corecompositor.cpp
+@@ -27,6 +27,7 @@
+ ****************************************************************************/
+ 
+ #include "corecompositor.h"
++#include <thread>
+ 
+ namespace MockCompositor {
+ 
diff -Nru qtwayland-opensource-src-5.15.2/debian/patches/series qtwayland-opensource-src-5.15.2/debian/patches/series
--- qtwayland-opensource-src-5.15.2/debian/patches/series	2021-07-10 10:22:01.000000000 +0000
+++ qtwayland-opensource-src-5.15.2/debian/patches/series	2021-08-16 12:46:20.000000000 +0000
@@ -1,2 +1,3 @@
 skip_animated_cursor_test.diff
 fix_dead_keys.diff
+gcc_11.diff
diff -Nru qtwayland-opensource-src-5.15.2/debian/watch qtwayland-opensource-src-5.15.2/debian/watch
--- qtwayland-opensource-src-5.15.2/debian/watch	2021-07-10 10:22:01.000000000 +0000
+++ qtwayland-opensource-src-5.15.2/debian/watch	2021-08-16 12:46:20.000000000 +0000
@@ -1,2 +1,2 @@
-version=3
-https://download.qt.io/official_releases/qt/([\d\.]*)/([\d\.]*)/submodules/qtwayland-everywhere-src-(.*)\.tar\.xz
+version=4
+https://download.qt.io/archive/qt/5.15/([\d\.]*)/submodules/qtwayland-everywhere-src-(.*)\.tar\.xz