diff --git a/src/Mod/TechDraw/Gui/DlgPrefsTechDraw1Imp.cpp b/src/Mod/TechDraw/Gui/DlgPrefsTechDraw1Imp.cpp
index cc6d891306..3a3bf22c3e 100644
--- a/src/Mod/TechDraw/Gui/DlgPrefsTechDraw1Imp.cpp
+++ b/src/Mod/TechDraw/Gui/DlgPrefsTechDraw1Imp.cpp
@@ -35,6 +35,7 @@ DlgPrefsTechDraw1Imp::DlgPrefsTechDraw1Imp( QWidget* parent )
 {
     this->setupUi(this);
     plsb_LabelSize->setUnit(Base::Unit::Length);
+    plsb_LabelSize->setMinimum(0);
 }
 
 DlgPrefsTechDraw1Imp::~DlgPrefsTechDraw1Imp()
diff --git a/src/Mod/TechDraw/Gui/DlgPrefsTechDraw2Imp.cpp b/src/Mod/TechDraw/Gui/DlgPrefsTechDraw2Imp.cpp
index d554a278ec..dd02aa5360 100644
--- a/src/Mod/TechDraw/Gui/DlgPrefsTechDraw2Imp.cpp
+++ b/src/Mod/TechDraw/Gui/DlgPrefsTechDraw2Imp.cpp
@@ -36,6 +36,8 @@ DlgPrefsTechDraw2Imp::DlgPrefsTechDraw2Imp( QWidget* parent )
     this->setupUi(this);
 
     this->pdsbTemplateMark->setUnit(Base::Unit::Length);
+    this->pdsbTemplateMark->setMinimum(0);
+
     connect(this->cbViewScaleType, SIGNAL(currentIndexChanged(int)),
         this, SLOT(onScaleTypeChanged(int)));
 }
diff --git a/src/Mod/TechDraw/Gui/DlgPrefsTechDraw3Imp.cpp b/src/Mod/TechDraw/Gui/DlgPrefsTechDraw3Imp.cpp
index f31be644a9..8587e11605 100644
--- a/src/Mod/TechDraw/Gui/DlgPrefsTechDraw3Imp.cpp
+++ b/src/Mod/TechDraw/Gui/DlgPrefsTechDraw3Imp.cpp
@@ -43,8 +43,11 @@ DlgPrefsTechDraw3Imp::DlgPrefsTechDraw3Imp( QWidget* parent )
 {
     this->setupUi(this);
     plsb_FontSize->setUnit(Base::Unit::Length);
+    plsb_FontSize->setMinimum(0);
     plsb_ArrowSize->setUnit(Base::Unit::Length);
+    plsb_ArrowSize->setMinimum(0);
     pdsbBalloonKink->setUnit(Base::Unit::Length);
+    pdsbBalloonKink->setMinimum(0);
 }
 
 DlgPrefsTechDraw3Imp::~DlgPrefsTechDraw3Imp()