diff --git a/_unittest/test_08_Primitives3D.py b/_unittest/test_08_Primitives3D.py
index 9a4e81c7e8a..50e7c2b1faf 100644
--- a/_unittest/test_08_Primitives3D.py
+++ b/_unittest/test_08_Primitives3D.py
@@ -1145,10 +1145,11 @@ def test_66c_group_components(self):
         )
 
     def test_66d_component_bounding_box(self):
+        self.aedtapp["tau_variable"] = "0.65"
         my_udmPairs = []
         mypair = ["OuterRadius", "20.2mm"]
         my_udmPairs.append(mypair)
-        mypair = ["Tau", "0.65"]
+        mypair = ["Tau", "tau_variable"]
         my_udmPairs.append(mypair)
         mypair = ["Sigma", "0.81"]
         my_udmPairs.append(mypair)
diff --git a/pyaedt/modeler/cad/Primitives3D.py b/pyaedt/modeler/cad/Primitives3D.py
index 47fc6dbf445..6f0b151e6a3 100644
--- a/pyaedt/modeler/cad/Primitives3D.py
+++ b/pyaedt/modeler/cad/Primitives3D.py
@@ -993,6 +993,10 @@ def create_udm(
                 vArgParamVector.append(
                     ["NAME:UDMParam", "Name:=", name_param, "Value:=", str(val), "PropType2:=", 3, "PropFlag2:=", 4]
                 )
+            elif val in self._app.variable_manager.variables:
+                vArgParamVector.append(
+                    ["NAME:UDMParam", "Name:=", name_param, "Value:=", str(val), "PropType2:=", 3, "PropFlag2:=", 2]
+                )
             else:
                 vArgParamVector.append(
                     [