diff --git a/src/Mod/MeshPart/Gui/Tessellation.cpp b/src/Mod/MeshPart/Gui/Tessellation.cpp
index cd43aedbf..b614d3bbb 100644
--- a/src/Mod/MeshPart/Gui/Tessellation.cpp
+++ b/src/Mod/MeshPart/Gui/Tessellation.cpp
@@ -245,7 +245,7 @@ bool Tessellation::accept()
 
             QString cmd;
             if (method == 0) { // Standard
-                double devFace = ui->spinSurfaceDeviation->value();
+                double devFace = ui->spinSurfaceDeviation->value().getValue();
                 cmd = QString::fromLatin1(
                     "__doc__=FreeCAD.getDocument(\"%1\")\n"
                     "__mesh__=__doc__.addObject(\"Mesh::Feature\",\"Mesh\")\n"
@@ -259,7 +259,7 @@ bool Tessellation::accept()
                     .arg(label);
             }
             else if (method == 1) { // Mefisto
-                double maxEdge = ui->spinMaximumEdgeLength->value();
+                double maxEdge = ui->spinMaximumEdgeLength->value().getValue();
                 if (!ui->spinMaximumEdgeLength->isEnabled())
                     maxEdge = 0;
                 cmd = QString::fromLatin1(
diff --git a/src/Mod/MeshPart/Gui/Tessellation.ui b/src/Mod/MeshPart/Gui/Tessellation.ui
index 463619ef3..2071f60af 100644
--- a/src/Mod/MeshPart/Gui/Tessellation.ui
+++ b/src/Mod/MeshPart/Gui/Tessellation.ui
@@ -70,9 +70,9 @@
              </widget>
             </item>
             <item>
-             <widget class="QDoubleSpinBox" name="spinSurfaceDeviation">
-              <property name="decimals">
-               <number>3</number>
+             <widget class="Gui::QuantitySpinBox" name="spinSurfaceDeviation">
+              <property name="unit" stdset="0">
+               <string notr="true">mm</string>
               </property>
               <property name="minimum">
                <double>0.001000000000000</double>
@@ -117,9 +117,9 @@
              </widget>
             </item>
             <item>
-             <widget class="QDoubleSpinBox" name="spinMaximumEdgeLength">
-              <property name="decimals">
-               <number>3</number>
+             <widget class="Gui::QuantitySpinBox" name="spinMaximumEdgeLength">
+              <property name="unit" stdset="0">
+               <string notr="true">mm</string>
               </property>
               <property name="singleStep">
                <double>0.100000000000000</double>
@@ -339,6 +339,13 @@
    </item>
   </layout>
  </widget>
+ <customwidgets>
+  <customwidget>
+   <class>Gui::QuantitySpinBox</class>
+   <extends>QWidget</extends>
+   <header>Gui/QuantitySpinBox.h</header>
+  </customwidget>
+ </customwidgets>
  <tabstops>
   <tabstop>treeWidget</tabstop>
  </tabstops>