diff --git a/src/app/main.cpp b/src/app/main.cpp
index 68bb014b3a8d97b9cf1e9b8699c1533fd7acdbe0..d96ef92ba74708ca0158872d029990be67efdf40 100644
--- a/src/app/main.cpp
+++ b/src/app/main.cpp
@@ -54,6 +54,14 @@ main(int argc, char* argv[])
     }
     setenv("QML_DISABLE_DISK_CACHE", "1", true);
 
+    /*
+     * Not quite sure why the GTK theme is not applied on Wayland when
+     * using the wayland platform plugin, but we can force XCB to make
+     * sure it works when X11 is available, otherwise fallback to Wayland.
+     * Could be related to: https://bugreports.qt.io/browse/QTBUG-99684.
+     */
+    setenv("QT_QPA_PLATFORM", "xcb:wayland", true);
+
     /*
      * Some GNU/Linux distros, like Zorin OS, set QT_STYLE_OVERRIDE
      * to force a particular Qt style.  This has been fine with Qt5