diff --git a/xdgshellclient.cpp b/xdgshellclient.cpp
--- a/xdgshellclient.cpp
+++ b/xdgshellclient.cpp
@@ -223,8 +223,12 @@
     }
 
     if (needsPlacement) {
-        const QRect area = workspace()->clientArea(PlacementArea, Screens::self()->current(), desktop());
-        placeIn(area);
+        if (isFullScreen()) {
+            setFrameGeometry(workspace()->clientArea(FullScreenArea, this));
+        } else {
+            const QRect area = workspace()->clientArea(PlacementArea, Screens::self()->current(), desktop());
+            placeIn(area);
+        }
     }
 
     m_requestGeometryBlockCounter--;
@@ -1501,6 +1505,9 @@
         return;
     }
 
+    if (!isMaximizable()) {
+        return;
+    }
     m_maximizeMode = maximizeMode;
     updateWindowRules(Rules::MaximizeHoriz | Rules::MaximizeVert | Rules::Position | Rules::Size);