diff --git a/src/Mod/Sketcher/App/Constraint.cpp b/src/Mod/Sketcher/App/Constraint.cpp
index c16531e35d..02b798b3fb 100644
--- a/src/Mod/Sketcher/App/Constraint.cpp
+++ b/src/Mod/Sketcher/App/Constraint.cpp
@@ -136,6 +136,7 @@ Quantity Constraint::getPresentationValue() const
     switch (Type) {
     case Distance:
     case Radius:
+    case Diameter:
     case DistanceX:
     case DistanceY:
         quantity.setValue(Value);
diff --git a/src/Mod/Sketcher/App/Constraint.h b/src/Mod/Sketcher/App/Constraint.h
index 0c888e6ba8..dee3c09a7a 100644
--- a/src/Mod/Sketcher/App/Constraint.h
+++ b/src/Mod/Sketcher/App/Constraint.h
@@ -56,6 +56,7 @@ enum ConstraintType {
     InternalAlignment = 15,
     SnellsLaw = 16,
     Block = 17,
+    Diameter = 18,
     NumConstraintTypes // must be the last item!
 };