diff --git a/tabbox/tabbox.cpp b/tabbox/tabbox.cpp
index 3c6a460b63..f5da53b34c 100644
--- a/tabbox/tabbox.cpp
+++ b/tabbox/tabbox.cpp
@@ -1120,7 +1120,7 @@ void TabBox::slotWalkBackThroughDesktopList()
     }
 }
 
-void TabBox::shadeActivate(Client *c)
+void TabBox::shadeActivate(AbstractClient *c)
 {
     if ((c->shadeMode() == ShadeNormal || c->shadeMode() == ShadeHover) && options->isShadeHover())
         c->setShade(ShadeActivated);
diff --git a/tabbox/tabbox.h b/tabbox/tabbox.h
index c3cfaedda5..ed4fed1460 100644
--- a/tabbox/tabbox.h
+++ b/tabbox/tabbox.h
@@ -233,7 +233,7 @@ private:
     template <typename Slot>
     void key(const char *actionName, Slot slot, const QKeySequence &shortcut = QKeySequence());
 
-    void shadeActivate(Client *c);
+    void shadeActivate(AbstractClient *c);
 
 private Q_SLOTS:
     void reconfigure();