diff --git a/libtaskmanager/abstracttasksmodel.h b/libtaskmanager/abstracttasksmodel.h
--- a/libtaskmanager/abstracttasksmodel.h
+++ b/libtaskmanager/abstracttasksmodel.h
@@ -85,7 +85,12 @@
         IsDemandingAttention, /**< Task is demanding attention. */
         SkipTaskbar,      /**< Task should not be shown in a 'task bar' user interface. */
         SkipPager,        /**< Task should not to be shown in a 'pager' user interface. */
-        AppPid,           /**< Application Process ID */
+        AppPid,           /**< Application Process ID. This is provided best-effort, and may not
+                               be what you expect: For window tasks owned by processes started
+                               from e.g. kwin_wayland, it would be the process id of kwin
+                               itself. DO NOT use this for destructive actions such as closing
+                               the application. The intended use case is to try and (smartly)
+                               gather more information about the task when needed. */
     };
     Q_ENUM(AdditionalRoles)
 
diff --git a/libtaskmanager/waylandtasksmodel.cpp b/libtaskmanager/waylandtasksmodel.cpp
--- a/libtaskmanager/waylandtasksmodel.cpp
+++ b/libtaskmanager/waylandtasksmodel.cpp
@@ -226,6 +226,10 @@
     QObject::connect(window, &KWayland::Client::PlasmaWindow::skipTaskbarChanged, q,
         [window, this] { this->dataChanged(window, SkipTaskbar); }
     );
+
+    QObject::connect(window, &KWayland::Client::PlasmaWindow::pidChanged, q,
+         [window, this] { this->dataChanged(window, AppPid); }
+    );
 }
 
 AppData WaylandTasksModel::Private::appData(KWayland::Client::PlasmaWindow *window)
@@ -333,7 +337,7 @@
     } else if (role == SkipPager) {
         // FIXME Implement.
     } else if (role == AppPid) {
-        // FIXME Implement.
+        return window->pid();
     }
 
     return QVariant();