diff --git a/mars/tools/StackVisualizer.java b/mars/tools/StackVisualizer.java
index 4c17f4b..100e437 100644
--- a/mars/tools/StackVisualizer.java
+++ b/mars/tools/StackVisualizer.java
@@ -130,7 +130,7 @@ protected JComponent buildMainDisplayArea() {
 		c.gridy = 0;
 		c.weighty = 1.0;
 		panel = new JPanel(new GridBagLayout());
-		panel.setPreferredSize(new Dimension(600, 650));
+		panel.setPreferredSize(new Dimension(600, 600));
 		for (String s : colNamesWhenDataPerByte)
 			tableModel.addColumn(s);
 		table = new JTable(tableModel);