diff --git a/xdgshellclient.cpp b/xdgshellclient.cpp
--- a/xdgshellclient.cpp
+++ b/xdgshellclient.cpp
@@ -222,6 +222,10 @@
         updateWindowRules(Rules::All);
     }
 
+    if (isFullScreen()) {
+        needsPlacement = false;
+    }
+
     if (needsPlacement) {
         const QRect area = workspace()->clientArea(PlacementArea, Screens::self()->current(), desktop());
         placeIn(area);
@@ -1501,6 +1505,9 @@
         return;
     }
 
+    if (!isMaximizable()) {
+        return;
+    }
     m_maximizeMode = maximizeMode;
     updateWindowRules(Rules::MaximizeHoriz | Rules::MaximizeVert | Rules::Position | Rules::Size);