diff --git a/qt/lc_qpreferencesdialog.cpp b/qt/lc_qpreferencesdialog.cpp
index a2249895..2916deed 100644
--- a/qt/lc_qpreferencesdialog.cpp
+++ b/qt/lc_qpreferencesdialog.cpp
@@ -28,7 +28,6 @@ lcQPreferencesDialog::lcQPreferencesDialog(QWidget* Parent, lcPreferencesDialogO
 	delete ui->povrayLayout;
 #endif
 
-	ui->lineWidth->setValidator(new QDoubleValidator(ui->lineWidth));
 	connect(ui->FadeStepsColor, SIGNAL(clicked()), this, SLOT(ColorButtonClicked()));
 	connect(ui->HighlightNewPartsColor, SIGNAL(clicked()), this, SLOT(ColorButtonClicked()));
 	connect(ui->gridStudColor, SIGNAL(clicked()), this, SLOT(ColorButtonClicked()));
@@ -69,7 +68,21 @@ lcQPreferencesDialog::lcQPreferencesDialog(QWidget* Parent, lcPreferencesDialogO
 	else
 		ui->antiAliasingSamples->setCurrentIndex(0);
 	ui->edgeLines->setChecked(mOptions->Preferences.mDrawEdgeLines);
-	ui->lineWidth->setText(lcFormatValueLocalized(mOptions->Preferences.mLineWidth));
+
+	if (QGLFormat::defaultFormat().sampleBuffers() && QGLFormat::defaultFormat().samples() > 1)
+	{
+		glGetFloatv(GL_SMOOTH_LINE_WIDTH_RANGE, mLineWidthRange);
+		glGetFloatv(GL_SMOOTH_LINE_WIDTH_GRANULARITY, &mLineWidthGranularity);
+	}
+	else
+	{
+		glGetFloatv(GL_ALIASED_LINE_WIDTH_RANGE, mLineWidthRange);
+		mLineWidthGranularity = 1.0f;
+	}
+
+	ui->LineWidthSlider->setRange(0, (mLineWidthRange[1] - mLineWidthRange[0]) / mLineWidthGranularity);
+	ui->LineWidthSlider->setValue((mOptions->Preferences.mLineWidth - mLineWidthRange[0]) / mLineWidthGranularity);
+
 	ui->MeshLOD->setChecked(mOptions->Preferences.mAllowLOD);
 	ui->FadeSteps->setChecked(mOptions->Preferences.mFadeSteps);
 	ui->HighlightNewParts->setChecked(mOptions->Preferences.mHighlightNewParts);
@@ -137,6 +150,7 @@ lcQPreferencesDialog::lcQPreferencesDialog(QWidget* Parent, lcPreferencesDialogO
 	on_studLogo_toggled();
 	on_antiAliasing_toggled();
 	on_edgeLines_toggled();
+	on_LineWidthSlider_valueChanged();
 	on_FadeSteps_toggled();
 	on_HighlightNewParts_toggled();
 	on_gridStuds_toggled();
@@ -205,7 +219,7 @@ void lcQPreferencesDialog::accept()
 		mOptions->AASamples = 2;
 
 	mOptions->Preferences.mDrawEdgeLines = ui->edgeLines->isChecked();
-	mOptions->Preferences.mLineWidth = lcParseValueLocalized(ui->lineWidth->text());
+	mOptions->Preferences.mLineWidth = mLineWidthRange[0] + static_cast<float>(ui->LineWidthSlider->value()) * mLineWidthGranularity;
 	mOptions->Preferences.mAllowLOD = ui->MeshLOD->isChecked();
 	mOptions->Preferences.mFadeSteps = ui->FadeSteps->isChecked();
 	mOptions->Preferences.mHighlightNewParts = ui->HighlightNewParts->isChecked();
@@ -375,7 +389,14 @@ void lcQPreferencesDialog::on_antiAliasing_toggled()
 
 void lcQPreferencesDialog::on_edgeLines_toggled()
 {
-	ui->lineWidth->setEnabled(ui->edgeLines->isChecked());
+	ui->LineWidthSlider->setEnabled(ui->edgeLines->isChecked());
+	ui->LineWidthLabel->setEnabled(ui->edgeLines->isChecked());
+}
+
+void lcQPreferencesDialog::on_LineWidthSlider_valueChanged()
+{
+	float Value = mLineWidthRange[0] + static_cast<float>(ui->LineWidthSlider->value()) * mLineWidthGranularity;
+	ui->LineWidthLabel->setText(QString::number(Value));
 }
 
 void lcQPreferencesDialog::on_FadeSteps_toggled()
diff --git a/qt/lc_qpreferencesdialog.h b/qt/lc_qpreferencesdialog.h
index 324c230e..9fe1f670 100644
--- a/qt/lc_qpreferencesdialog.h
+++ b/qt/lc_qpreferencesdialog.h
@@ -35,6 +35,7 @@ public slots:
 	void ColorButtonClicked();
 	void on_antiAliasing_toggled();
 	void on_edgeLines_toggled();
+	void on_LineWidthSlider_valueChanged();
 	void on_FadeSteps_toggled();
 	void on_HighlightNewParts_toggled();
 	void on_gridStuds_toggled();
@@ -68,5 +69,7 @@ private:
 	void UpdateMouseTree();
 	void UpdateMouseTreeItem(int ItemIndex);
 	void setShortcutModified(QTreeWidgetItem *treeItem, bool modified);
-};
 
+	float mLineWidthRange[2];
+	float mLineWidthGranularity;
+};
diff --git a/qt/lc_qpreferencesdialog.ui b/qt/lc_qpreferencesdialog.ui
index 6c254830..4bbb64f1 100644
--- a/qt/lc_qpreferencesdialog.ui
+++ b/qt/lc_qpreferencesdialog.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>598</width>
-    <height>492</height>
+    <height>494</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -391,16 +391,6 @@
             </property>
            </widget>
           </item>
-          <item row="2" column="1">
-           <widget class="QLineEdit" name="lineWidth">
-            <property name="maximumSize">
-             <size>
-              <width>75</width>
-              <height>16777215</height>
-             </size>
-            </property>
-           </widget>
-          </item>
           <item row="0" column="0">
            <widget class="QCheckBox" name="antiAliasing">
             <property name="text">
@@ -441,13 +431,6 @@
             </item>
            </widget>
           </item>
-          <item row="2" column="2">
-           <widget class="QLabel" name="label_2">
-            <property name="text">
-             <string>width</string>
-            </property>
-           </widget>
-          </item>
           <item row="4" column="0">
            <widget class="QCheckBox" name="axisIcon">
             <property name="text">
@@ -476,6 +459,29 @@
             </property>
            </widget>
           </item>
+          <item row="2" column="1">
+           <widget class="QSlider" name="LineWidthSlider">
+            <property name="sizePolicy">
+             <sizepolicy hsizetype="Minimum" vsizetype="Fixed">
+              <horstretch>0</horstretch>
+              <verstretch>0</verstretch>
+             </sizepolicy>
+            </property>
+            <property name="orientation">
+             <enum>Qt::Horizontal</enum>
+            </property>
+            <property name="tickPosition">
+             <enum>QSlider::NoTicks</enum>
+            </property>
+           </widget>
+          </item>
+          <item row="2" column="3">
+           <widget class="QLabel" name="LineWidthLabel">
+            <property name="text">
+             <string/>
+            </property>
+           </widget>
+          </item>
          </layout>
         </widget>
        </item>
@@ -1220,7 +1226,8 @@
   <tabstop>studLogo</tabstop>
   <tabstop>studLogoCombo</tabstop>
   <tabstop>edgeLines</tabstop>
-  <tabstop>lineWidth</tabstop>
+  <tabstop>LineWidthSlider</tabstop>
+  <tabstop>LineWidthLabel</tabstop>
   <tabstop>MeshLOD</tabstop>
   <tabstop>axisIcon</tabstop>
   <tabstop>FadeSteps</tabstop>