diff --git a/qcross/ccrossfieldwidget.cpp b/qcross/ccrossfieldwidget.cpp
index 1a9a6b7..9f00fef 100644
--- a/qcross/ccrossfieldwidget.cpp
+++ b/qcross/ccrossfieldwidget.cpp
@@ -427,6 +427,8 @@ namespace qcross {
 	}
 	
 	void CCrossFieldWidget::execMark(int x, int y, MarkerType & marker) {
+		if (m_Solved) return;
+		
 		switch (marker) {
 		case CMT_MARKED:
 			if (m_Picture->solution().pixel(x, y)) {