diff --git a/core/MembershipQE.cpp b/core/MembershipQE.cpp
index 01a58d05..521e6136 100644
--- a/core/MembershipQE.cpp
+++ b/core/MembershipQE.cpp
@@ -554,25 +554,25 @@ void ClubStatusQuery::getClubStatus(const QString &in_callsign,
     while ( ++records && query.next() )
     {
         QString clubid = query.value(0).toString();
-        QVariant band = query.value(1);
-        QVariant mode = query.value(2);
+        QString band = query.value(1).toString();
+        QString mode = query.value(2).toString();
         QVariant confirmed = query.value(3);
-        QVariant current_mode = query.value(4);
+        QString current_mode = query.value(4).toString();
 
         qCDebug(runtime) << "Processing" << currentProcessedClub
                          << clubid
-                         << band.isNull() << band
-                         << mode.isNull() << mode
-                         << confirmed.isNull() << confirmed
-                         << current_mode.isNull();
+                         << band.isEmpty() << band
+                         << mode.isEmpty() << mode
+                         << confirmed.toString().isEmpty() << confirmed
+                         << current_mode.isEmpty();
 
         // the select generates starting line for a new club
         // Changing the club
         if ( currentProcessedClub != clubid
-             && band.isNull()
-             && mode.isNull()
-             && confirmed.isNull()
-             && current_mode.isNull()  )
+             && band.isEmpty()
+             && mode.isEmpty()
+             && confirmed.toString().isEmpty()
+             && current_mode.isEmpty()  )
         {
             if ( !currentProcessedClub.isEmpty() )
             {
@@ -591,10 +591,10 @@ void ClubStatusQuery::getClubStatus(const QString &in_callsign,
 
         if ( currentProcessedClub == clubid )
         {
-            if ( band.toString() == in_band )
+            if ( band == in_band )
             {
                 bandMatched = true;
-                if ( mode.toString() == current_mode.toString() )
+                if ( mode == current_mode )
                 {
                     bandModeMatched = true;
 
@@ -605,7 +605,7 @@ void ClubStatusQuery::getClubStatus(const QString &in_callsign,
                 }
             }
 
-            if ( mode.toString() == current_mode.toString() )
+            if ( mode == current_mode )
             {
                 modeMatched = true;
             }
diff --git a/core/main.cpp b/core/main.cpp
index 2114b254..29de409f 100644
--- a/core/main.cpp
+++ b/core/main.cpp
@@ -408,7 +408,7 @@ int main(int argc, char* argv[])
     QString lang = parser.value(forceLanguage);
 
     app.setOrganizationName("hamradio");
-    app.setApplicationName("QLog" + ((environment.isNull()) ? "" : environment.prepend("-")));
+    app.setApplicationName("QLog" + ((environment.isEmpty()) ? "" : environment.prepend("-")));
 
     /* If the Style parameter is not present then use a default - Fusion style */
     if ( !stylePresent )
diff --git a/data/Data.cpp b/data/Data.cpp
index 1a4c292f..4ab289b0 100644
--- a/data/Data.cpp
+++ b/data/Data.cpp
@@ -184,24 +184,24 @@ DxccStatus Data::dxccStatus(int dxcc, const QString &band, const QString &mode)
 
     if ( query.next() )
     {
-        if ( query.value(0).isNull() )
+        if ( query.value(0).toString().isEmpty() )
             return DxccStatus::NewEntity;
 
-        if ( query.value(1).isNull() )
+        if ( query.value(1).toString().isEmpty() )
         {
-            if ( query.value(2).isNull() )
+            if ( query.value(2).toString().isEmpty() )
                 return DxccStatus::NewBandMode;
             else
                 return DxccStatus::NewBand;
         }
 
-        if ( query.value(2).isNull() )
+        if ( query.value(2).toString().isEmpty() )
             return DxccStatus::NewMode;
 
-        if ( query.value(3).isNull() )
+        if ( query.value(3).toString().isEmpty() )
             return DxccStatus::NewSlot;
 
-        if ( query.value(4).isNull() )
+        if ( query.value(4).toString().isEmpty() )
             return DxccStatus::Worked;
         else
             return DxccStatus::Confirmed;
diff --git a/ui/AlertWidget.cpp b/ui/AlertWidget.cpp
index 0690a625..fd45d811 100644
--- a/ui/AlertWidget.cpp
+++ b/ui/AlertWidget.cpp
@@ -131,11 +131,11 @@ void AlertWidget::restoreTableHeaderState()
 {
     FCT_IDENTIFICATION;
 
-    const QVariant &state = settings.value("alert/state");
+    const QByteArray &state = settings.value("alert/state").toByteArray();
 
-    if (!state.isNull())
+    if (!state.isEmpty())
     {
-        ui->alertTableView->horizontalHeader()->restoreState(state.toByteArray());
+        ui->alertTableView->horizontalHeader()->restoreState(state);
     }
 }
 
diff --git a/ui/DxWidget.cpp b/ui/DxWidget.cpp
index 29594fb7..0f68bb02 100644
--- a/ui/DxWidget.cpp
+++ b/ui/DxWidget.cpp
@@ -793,31 +793,32 @@ void DxWidget::restoreWidgetSetting()
     FCT_IDENTIFICATION;
 
     QSettings settings;
-    QVariant state = settings.value("dxc/dxtablestate");
+    QByteArray state = settings.value("dxc/dxtablestate").toByteArray();
 
-    if (!state.isNull())
+    if (!state.isEmpty())
     {
-        ui->dxTable->horizontalHeader()->restoreState(state.toByteArray());
+        ui->dxTable->horizontalHeader()->restoreState(state);
     }
 
-    state = settings.value("dxc/wcytablestate");
+    state = settings.value("dxc/wcytablestate").toByteArray();
 
-    if (!state.isNull())
+    if (!state.isEmpty())
     {
-        ui->wcyTable->horizontalHeader()->restoreState(state.toByteArray());
+        ui->wcyTable->horizontalHeader()->restoreState(state);
     }
 
-    state = settings.value("dxc/wwvtablestate");
+    state = settings.value("dxc/wwvtablestate").toByteArray();
 
-    if (!state.isNull())
+    if (!state.isEmpty())
     {
-        ui->wwvTable->horizontalHeader()->restoreState(state.toByteArray());
+        ui->wwvTable->horizontalHeader()->restoreState(state);
     }
-    state = settings.value("dxc/toalltablestate");
 
-    if (!state.isNull())
+    state = settings.value("dxc/toalltablestate").toByteArray();
+
+    if (!state.isEmpty())
     {
-        ui->toAllTable->horizontalHeader()->restoreState(state.toByteArray());
+        ui->toAllTable->horizontalHeader()->restoreState(state);
     }
 
     int fontsize = settings.value("dxc/consolefontsize", -1).toInt();
diff --git a/ui/LogbookWidget.cpp b/ui/LogbookWidget.cpp
index c8416e23..d858e10a 100644
--- a/ui/LogbookWidget.cpp
+++ b/ui/LogbookWidget.cpp
@@ -139,9 +139,9 @@ LogbookWidget::LogbookWidget(QWidget *parent) :
     ui->contactTable->setItemDelegateForColumn(LogbookModel::COLUMN_UKSMG, new UnitFormatDelegate("", 0, 1, ui->contactTable));
 
     QSettings settings;
-    QVariant logbookState = settings.value("logbook/state");
-    if (!logbookState.isNull()) {
-        ui->contactTable->horizontalHeader()->restoreState(logbookState.toByteArray());
+    const QByteArray &logbookState = settings.value("logbook/state").toByteArray();
+    if (!logbookState.isEmpty()) {
+        ui->contactTable->horizontalHeader()->restoreState(logbookState);
     }
     else {
         /* Hide all */
diff --git a/ui/RigWidget.cpp b/ui/RigWidget.cpp
index 5e754fdc..a5c6db59 100644
--- a/ui/RigWidget.cpp
+++ b/ui/RigWidget.cpp
@@ -197,7 +197,7 @@ void RigWidget::bandComboChanged(const QString &newBand)
 
     double newFreq = record.value("start_freq").toDouble();
 
-    if ( ! record.value("last_seen_freq").isNull() )
+    if ( ! record.value("last_seen_freq").toString().isEmpty() )
     {
         newFreq = record.value("last_seen_freq").toDouble();
     }
diff --git a/ui/WsjtxWidget.cpp b/ui/WsjtxWidget.cpp
index d730b027..3e98dc76 100644
--- a/ui/WsjtxWidget.cpp
+++ b/ui/WsjtxWidget.cpp
@@ -335,11 +335,11 @@ void WsjtxWidget::restoreTableHeaderState()
     FCT_IDENTIFICATION;
 
     QSettings settings;
-    QVariant state = settings.value("wsjtx/state");
+    const QByteArray &state = settings.value("wsjtx/state").toByteArray();
 
-    if (!state.isNull())
+    if (!state.isEmpty())
     {
-        ui->tableView->horizontalHeader()->restoreState(state.toByteArray());
+        ui->tableView->horizontalHeader()->restoreState(state);
     }
 }