diff --git a/internal/system/hierarchy.go b/internal/system/hierarchy.go
index a1ffb24..87cf7fa 100644
--- a/internal/system/hierarchy.go
+++ b/internal/system/hierarchy.go
@@ -341,15 +341,21 @@ func (this *Hierarchy) drawBackgroundPart (canvas.Canvas) {
 	// if so, windows should be transparent if the color has transparency
 }
 
+// var minimumSizeCount = 0
 func (this *Hierarchy) doMinimumSize () {
 	this.minimumClean = true
+	// println("doMinimumSize", minimumSizeCount)
+	// minimumSizeCount ++
 
+	previousMinimumSize := this.minimumSize
 	this.minimumSize = image.Point { }
 	if this.root != nil {
 		this.minimumSize = this.root.minimumSize()
 	}
 
-	this.link.NotifyMinimumSizeChange()
+	if previousMinimumSize != this.minimumSize {
+		this.link.NotifyMinimumSizeChange()
+	}
 }
 
 func (this *Hierarchy) newStyleApplicator () *styleApplicator {