diff --git a/sdrbase/gui/glspectrumgui.cpp b/sdrbase/gui/glspectrumgui.cpp
index a750e8fff..65b77acb1 100644
--- a/sdrbase/gui/glspectrumgui.cpp
+++ b/sdrbase/gui/glspectrumgui.cpp
@@ -26,7 +26,7 @@ GLSpectrumGUI::GLSpectrumGUI(QWidget* parent) :
 	m_invert(true)
 {
 	ui->setupUi(this);
-	for(int ref = 0; ref >= -95; ref -= 5)
+	for(int ref = 0; ref >= -110; ref -= 5)
 		ui->refLevel->addItem(QString("%1").arg(ref));
 	for(int range = 100; range >= 5; range -= 5)
 		ui->levelRange->addItem(QString("%1").arg(range));