diff --git a/libtaskmanager/abstracttasksmodel.h b/libtaskmanager/abstracttasksmodel.h
--- a/libtaskmanager/abstracttasksmodel.h
+++ b/libtaskmanager/abstracttasksmodel.h
@@ -83,6 +83,7 @@
         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 */
     };
     Q_ENUM(AdditionalRoles)
 
diff --git a/libtaskmanager/tasktools.h b/libtaskmanager/tasktools.h
--- a/libtaskmanager/tasktools.h
+++ b/libtaskmanager/tasktools.h
@@ -37,6 +37,7 @@
     QString genericName; // Generic application name.
     QIcon icon;
     QUrl url;
+    int pid;
 };
 
 enum UrlComparisonMode {
diff --git a/libtaskmanager/xwindowtasksmodel.cpp b/libtaskmanager/xwindowtasksmodel.cpp
--- a/libtaskmanager/xwindowtasksmodel.cpp
+++ b/libtaskmanager/xwindowtasksmodel.cpp
@@ -345,7 +345,7 @@
         || properties2 & (NET::WM2DesktopFileName | NET::WM2WindowClass)) {
         wipeInfoCache = true;
         wipeAppDataCache = true;
-        changedRoles << Qt::DisplayRole << Qt::DecorationRole << AppId << AppName << GenericName << LauncherUrl;
+        changedRoles << Qt::DisplayRole << Qt::DecorationRole << AppId << AppName << GenericName << LauncherUrl << AppPid;
     }
 
     if ((properties & NET::WMIcon) && !changedRoles.contains(Qt::DecorationRole)) {
@@ -427,20 +427,16 @@
 AppData XWindowTasksModel::Private::appData(WId window)
 {
     if (!appDataCache.contains(window)) {
-        const AppData &data = appDataFromUrl(windowUrl(window));
+        AppData data = appDataFromUrl(windowUrl(window));
+
+        data.pid = NETWinInfo(QX11Info::connection(), window, QX11Info::appRootWindow(), NET::WMPid, 0).pid();
 
         // If we weren't able to derive a launcher URL from the window meta data,
         // fall back to WM_CLASS Class string as app id. This helps with apps we
         // can't map to an URL due to existing outside the regular system
         // environment, e.g. wine clients.
         if (data.id.isEmpty() && data.url.isEmpty()) {
-            AppData dataCopy = data;
-
-            dataCopy.id = windowInfo(window)->windowClassClass();
-
-            appDataCache.insert(window, dataCopy);
-
-            return dataCopy;
+            data.id = windowInfo(window)->windowClassClass();
         }
 
         appDataCache.insert(window, data);
@@ -921,6 +917,8 @@
         return (info->hasState(NET::SkipTaskbar) || info->windowType(NET::UtilityMask) == NET::Utility);
     } else if (role == SkipPager) {
         return d->windowInfo(window)->hasState(NET::SkipPager);
+    } else if (role == AppPid) {
+        return d->appData(window).pid;
     }
 
     return QVariant();