diff --git a/src/PackageModel/PackageView.h b/src/PackageModel/PackageView.h
--- a/src/PackageModel/PackageView.h
+++ b/src/PackageModel/PackageView.h
@@ -29,6 +29,8 @@
 public:
     explicit PackageView(QWidget *parent = 0);
 
+    int selectionCount() const;
+
 protected Q_SLOTS:
     void currentChanged(const QModelIndex &current, const QModelIndex &previous);
     void selectionChanged(const QItemSelection &selected, const QItemSelection &deselected);
diff --git a/src/PackageModel/PackageView.cpp b/src/PackageModel/PackageView.cpp
--- a/src/PackageModel/PackageView.cpp
+++ b/src/PackageModel/PackageView.cpp
@@ -22,8 +22,6 @@
 
 #include "PackageViewHeader.h"
 
-#define NUM_COLUMNS 6 // If this is changed change PackageWidget.cpp value as well
-
 PackageView::PackageView(QWidget *parent)
     : QTreeView(parent)
 {
@@ -37,6 +35,11 @@
     header()->setDefaultAlignment(Qt::AlignLeft);
 }
 
+int PackageView::selectionCount() const
+{
+    return selectionModel()->selectedRows().count();
+}
+
 void PackageView::currentChanged(const QModelIndex &current, const QModelIndex &previous)
 {
     if (previous.row() != -1 && current.isValid()) {
@@ -49,14 +52,15 @@
 {
     QTreeView::selectionChanged(selected, deselected);
 
-    if (!selectedIndexes().size()) {
+    const int count = selectionCount();
+    if (count <= 0) {
         emit selectionEmpty();
         return;
     }
 
     if (!selected.indexes().isEmpty()) {
         emit currentPackageChanged(selected.indexes().first());
-        if(selectedIndexes().count()/NUM_COLUMNS > 1) {
+        if(count > 1) {
           emit selectionMulti();
         }
     }
diff --git a/src/PackageModel/PackageWidget.cpp b/src/PackageModel/PackageWidget.cpp
--- a/src/PackageModel/PackageWidget.cpp
+++ b/src/PackageModel/PackageWidget.cpp
@@ -55,8 +55,6 @@
 #include "PackageView.h"
 #include "PackageDelegate.h"
 
-#define NUM_COLUMNS 6 // If this is changed change PackageView.cpp value as well
-
 bool packageNameLessThan(QApt::Package *p1, QApt::Package *p2)
 {
      return p1->name() < p2->name();
@@ -110,7 +108,9 @@
     m_packageView->setModel(m_proxyModel);
     m_packageView->setItemDelegate(delegate);
     m_packageView->header()->setSectionResizeMode(0, QHeaderView::Stretch);
-    for (int i = 3; i < NUM_COLUMNS; ++i) {
+    const int numColumns = m_packageView->header()->count();
+    Q_ASSERT(numColumns >= 3);
+    for (int i = 3; i < numColumns; ++i) {
         m_packageView->header()->setSectionHidden(i, true);
     }
     topVBox->addWidget(m_packageView);
@@ -311,15 +311,14 @@
     menu.addSeparator();
     menu.addAction(m_lockAction);
 
-    const QModelIndexList selected = m_packageView->selectionModel()->selectedIndexes();
+    const int selected = m_packageView->selectionCount();
 
-    if (!selected.size()) {
+    if (selected <= 0) {
         return;
     }
 
-    // Divide by the number of columns
-    if (selected.size()/NUM_COLUMNS == 1) {
-        int state = m_proxyModel->packageAt(selected.first())->state();
+    if (selected == 1) {
+        int state = m_proxyModel->packageAt(m_packageView->currentIndex())->state();
         bool upgradeable = (state & QApt::Package::Upgradeable);
 
         if (state & QApt::Package::Installed) {