diff --git a/sdrbase/dsp/glspectrumsettings.cpp b/sdrbase/dsp/glspectrumsettings.cpp
index 42a926da3..1ea0fa9d3 100644
--- a/sdrbase/dsp/glspectrumsettings.cpp
+++ b/sdrbase/dsp/glspectrumsettings.cpp
@@ -110,7 +110,8 @@ bool GLSpectrumSettings::deserialize(const QByteArray& data)
 		m_fftWindow = (FFTWindow::Function) tmp;
 		d.readReal(4, &m_refLevel, 0);
 		d.readReal(5, &m_powerRange, 100);
-		d.readS32(26, &m_fpsPeriodMs, 50);
+		d.readS32(26, &tmp, 50);
+		m_fpsPeriodMs = tmp < 5 ? 5 : tmp > 500 ? 500 : tmp;
 		d.readBool(6, &m_displayWaterfall, true);
 		d.readBool(7, &m_invertedWaterfall, true);
 		d.readBool(8, &m_displayMaxHold, false);
diff --git a/sdrbase/webapi/webapiadapterbase.cpp b/sdrbase/webapi/webapiadapterbase.cpp
index 4a2a78285..e27b00039 100644
--- a/sdrbase/webapi/webapiadapterbase.cpp
+++ b/sdrbase/webapi/webapiadapterbase.cpp
@@ -370,8 +370,10 @@ void WebAPIAdapterBase::webapiUpdatePreset(
         if (spectrumIt->contains("refLevel")) {
             spectrumSettings.m_refLevel = apiPreset->getSpectrumConfig()->getRefLevel();
         }
-        if (spectrumIt->contains("fpsPeriodMs")) {
-            spectrumSettings.m_fpsPeriodMs = apiPreset->getSpectrumConfig()->getFpsPeriodMs();
+        if (spectrumIt->contains("fpsPeriodMs"))
+        {
+            qint32 fpsPeriodMs = apiPreset->getSpectrumConfig()->getFpsPeriodMs();
+            spectrumSettings.m_fpsPeriodMs = fpsPeriodMs < 5 ? 5 : fpsPeriodMs > 500 ? 500 : fpsPeriodMs;
         }
         if (spectrumIt->contains("waterfallShare")) {
             spectrumSettings.m_waterfallShare = apiPreset->getSpectrumConfig()->getWaterfallShare();
diff --git a/sdrgui/gui/glspectrum.cpp b/sdrgui/gui/glspectrum.cpp
index 8202645bc..dcc206809 100644
--- a/sdrgui/gui/glspectrum.cpp
+++ b/sdrgui/gui/glspectrum.cpp
@@ -440,10 +440,6 @@ void GLSpectrum::newSpectrum(const Real *spectrum, int nbBins, int fftSize)
 
 	updateWaterfall(spectrum);
 	updateHistogram(spectrum);
-
-	if (m_fpsPeriodMs == 0) {
-		update();
-	}
 }
 
 void GLSpectrum::updateWaterfall(const Real *spectrum)
diff --git a/sdrgui/gui/glspectrumgui.cpp b/sdrgui/gui/glspectrumgui.cpp
index ab1dc19fa..1ba1d046d 100644
--- a/sdrgui/gui/glspectrumgui.cpp
+++ b/sdrgui/gui/glspectrumgui.cpp
@@ -32,7 +32,7 @@
 #include "util/db.h"
 #include "ui_glspectrumgui.h"
 
-const int GLSpectrumGUI::m_fpsMs[] = {500, 200, 100, 50, 20, 10, 5, 0};
+const int GLSpectrumGUI::m_fpsMs[] = {500, 200, 100, 50, 20, 10, 5};
 
 GLSpectrumGUI::GLSpectrumGUI(QWidget* parent) :
 	QWidget(parent),
@@ -147,24 +147,17 @@ void GLSpectrumGUI::displaySettings()
 		}
 	}
 
-    if (m_settings.m_fpsPeriodMs == 0)
-    {
-        ui->fps->setCurrentIndex(sizeof(m_fpsMs)/sizeof(m_fpsMs[0]) - 1);
-    }
-    else
-    {
-        unsigned int i = 0;
+    unsigned int i = 0;
 
-        for (; i < sizeof(m_fpsMs)/sizeof(m_fpsMs[0]); i++)
-        {
-            if (m_settings.m_fpsPeriodMs >= m_fpsMs[i]) {
-                break;
-            }
+    for (; i < sizeof(m_fpsMs)/sizeof(m_fpsMs[0]); i++)
+    {
+        if (m_settings.m_fpsPeriodMs >= m_fpsMs[i]) {
+            break;
         }
-
-        ui->fps->setCurrentIndex(i);
     }
 
+    ui->fps->setCurrentIndex(i);
+
     ui->fftOverlap->setValue(m_settings.m_fftOverlap);
     setMaximumOverlap();
 	ui->averaging->setCurrentIndex(m_settings.m_averagingIndex);
diff --git a/sdrgui/gui/glspectrumgui.ui b/sdrgui/gui/glspectrumgui.ui
index 02a9c49bb..f256f1cac 100644
--- a/sdrgui/gui/glspectrumgui.ui
+++ b/sdrgui/gui/glspectrumgui.ui
@@ -461,7 +461,7 @@
         <string>Spectrum maximum FPS (NL for No Limit)</string>
        </property>
        <property name="currentIndex">
-        <number>3</number>
+        <number>0</number>
        </property>
        <item>
         <property name="text">
@@ -498,11 +498,6 @@
          <string>200</string>
         </property>
        </item>
-       <item>
-        <property name="text">
-         <string>NL</string>
-        </property>
-       </item>
       </widget>
      </item>
      <item>