diff --git a/Source/QtDialog/AddCacheEntry.cxx b/Source/QtDialog/AddCacheEntry.cxx
index b4d919193..00aaf69da 100644
--- a/Source/QtDialog/AddCacheEntry.cxx
+++ b/Source/QtDialog/AddCacheEntry.cxx
@@ -12,15 +12,16 @@
 
 #include "AddCacheEntry.h"
 #include <QMetaProperty>
+#include <QCompleter>
 
 static const int NumTypes = 4;
-static const QString TypeStrings[NumTypes] = 
+static const QString TypeStrings[NumTypes] =
   { "BOOL", "PATH", "FILEPATH", "STRING" };
-static const QCMakeProperty::PropertyType Types[NumTypes] = 
-  { QCMakeProperty::BOOL, QCMakeProperty::PATH, 
-    QCMakeProperty::FILEPATH, QCMakeProperty::STRING}; 
+static const QCMakeProperty::PropertyType Types[NumTypes] =
+  { QCMakeProperty::BOOL, QCMakeProperty::PATH,
+    QCMakeProperty::FILEPATH, QCMakeProperty::STRING};
 
-AddCacheEntry::AddCacheEntry(QWidget* p)
+AddCacheEntry::AddCacheEntry(QWidget* p, const QStringList& completions)
   : QWidget(p)
 {
   this->setupUi(this);
@@ -42,6 +43,7 @@ AddCacheEntry::AddCacheEntry(QWidget* p)
   this->setTabOrder(path, filepath);
   this->setTabOrder(filepath, string);
   this->setTabOrder(string, this->Description);
+  this->Name->setCompleter(new QCompleter(completions, this));
 }
 
 QString AddCacheEntry::name() const
diff --git a/Source/QtDialog/AddCacheEntry.h b/Source/QtDialog/AddCacheEntry.h
index db6baf9b1..e219d4ee7 100644
--- a/Source/QtDialog/AddCacheEntry.h
+++ b/Source/QtDialog/AddCacheEntry.h
@@ -15,6 +15,7 @@
 
 #include <QWidget>
 #include <QCheckBox>
+#include <QStringList>
 
 #include "QCMake.h"
 #include "ui_AddCacheEntry.h"
@@ -23,7 +24,7 @@ class AddCacheEntry : public QWidget, public Ui::AddCacheEntry
 {
   Q_OBJECT
 public:
-  AddCacheEntry(QWidget* p);
+  AddCacheEntry(QWidget* p, const QStringList& completions);
 
   QString name() const;
   QVariant value() const;
diff --git a/Source/QtDialog/CMakeSetupDialog.cxx b/Source/QtDialog/CMakeSetupDialog.cxx
index c8c4bfa5b..1c058d37c 100644
--- a/Source/QtDialog/CMakeSetupDialog.cxx
+++ b/Source/QtDialog/CMakeSetupDialog.cxx
@@ -68,6 +68,9 @@ CMakeSetupDialog::CMakeSetupDialog()
   int w = settings.value("Width", 700).toInt();
   this->resize(w, h);
 
+  this->AddVariableCompletions = settings.value("AddVariableCompletionEntries",
+                           QStringList("CMAKE_INSTALL_PREFIX")).toStringList();
+
   QWidget* cont = new QWidget(this);
   this->setupUi(cont);
   this->Splitter->setStretchFactor(0, 3);
@@ -1008,7 +1011,7 @@ void CMakeSetupDialog::addCacheEntry()
   dialog.resize(400, 200);
   dialog.setWindowTitle(tr("Add Cache Entry"));
   QVBoxLayout* l = new QVBoxLayout(&dialog);
-  AddCacheEntry* w = new AddCacheEntry(&dialog);
+  AddCacheEntry* w = new AddCacheEntry(&dialog, this->AddVariableCompletions);
   QDialogButtonBox* btns = new QDialogButtonBox(
       QDialogButtonBox::Ok | QDialogButtonBox::Cancel,
       Qt::Horizontal, &dialog);
@@ -1021,6 +1024,26 @@ void CMakeSetupDialog::addCacheEntry()
     {
     QCMakeCacheModel* m = this->CacheValues->cacheModel();
     m->insertProperty(w->type(), w->name(), w->description(), w->value(), false);
+
+    // only add variable names to the completion which are new
+    if (!this->AddVariableCompletions.contains(w->name()))
+      {
+      this->AddVariableCompletions << w->name();
+      // limit to at most 100 completion items
+      if (this->AddVariableCompletions.size() > 100)
+        {
+        this->AddVariableCompletions.removeFirst();
+        }
+      // make sure CMAKE_INSTALL_PREFIX is always there
+      if (!this->AddVariableCompletions.contains("CMAKE_INSTALL_PREFIX"))
+        {
+        this->AddVariableCompletions << QString("CMAKE_INSTALL_PREFIX");
+        }
+      QSettings settings;
+      settings.beginGroup("Settings/StartPath");
+      settings.setValue("AddVariableCompletionEntries",
+                        this->AddVariableCompletions);
+      }
     }
 }
 
diff --git a/Source/QtDialog/CMakeSetupDialog.h b/Source/QtDialog/CMakeSetupDialog.h
index 51217592a..259967580 100644
--- a/Source/QtDialog/CMakeSetupDialog.h
+++ b/Source/QtDialog/CMakeSetupDialog.h
@@ -36,7 +36,7 @@ public slots:
   void setBinaryDirectory(const QString& dir);
   void setSourceDirectory(const QString& dir);
 
-protected slots: 
+protected slots:
   void initialize();
   void doConfigure();
   void doGenerate();
@@ -46,7 +46,7 @@ protected slots:
   void doInterrupt();
   void error(const QString& message);
   void message(const QString& message);
-  
+
   void doSourceBrowse();
   void doBinaryBrowse();
   void doReloadCache();
@@ -105,6 +105,8 @@ protected:
   QTextCharFormat ErrorFormat;
   QTextCharFormat MessageFormat;
 
+  QStringList AddVariableCompletions;
+
   QEventLoop LocalLoop;
 
   float ProgressOffset;
@@ -118,8 +120,8 @@ class QCMakeThread : public QThread
 public:
   QCMakeThread(QObject* p);
   QCMake* cmakeInstance() const;
-  
-signals:  
+
+signals:
   void cmakeInitialized();
 
 protected: