diff --git a/Plugins/Libigl/stkLibiglCopyleft/stkLibiglBoolean3DMesher.cxx b/Plugins/Libigl/stkLibiglCopyleft/stkLibiglBoolean3DMesher.cxx
index e1716a6..39dd81a 100644
--- a/Plugins/Libigl/stkLibiglCopyleft/stkLibiglBoolean3DMesher.cxx
+++ b/Plugins/Libigl/stkLibiglCopyleft/stkLibiglBoolean3DMesher.cxx
@@ -199,14 +199,25 @@ int stkLibiglBoolean3DMesher::RequestData(vtkInformation *,
 	Eigen::MatrixXi outputMeshCells;
 	try
 	{
-		if (this->Mode >= Modes::UNION && this->Mode <= Modes::DIFFERENCE)
-		{
+		if (this->Mode == stkLibiglBoolean3DMesher::Modes::UNION) {
+			igl::copyleft::cgal::mesh_boolean(inputMeshAVerts, inputMeshACells,
+												inputMeshBVerts, inputMeshBCells,
+												igl::MeshBooleanType::MESH_BOOLEAN_TYPE_UNION,
+												outputMeshVerts, outputMeshCells);
+		}
+		else if (this->Mode == stkLibiglBoolean3DMesher::Modes::INTERSECTION) {
 			igl::copyleft::cgal::mesh_boolean(inputMeshAVerts, inputMeshACells,
 												inputMeshBVerts, inputMeshBCells,
-												static_cast<igl::MeshBooleanType>(this->Mode),
+												igl::MeshBooleanType::MESH_BOOLEAN_TYPE_INTERSECT,
+												outputMeshVerts, outputMeshCells);
+		}
+		else if (this->Mode == stkLibiglBoolean3DMesher::Modes::DIFFERENCE) {
+			igl::copyleft::cgal::mesh_boolean(inputMeshAVerts, inputMeshACells,
+												inputMeshBVerts, inputMeshBCells,
+												igl::MeshBooleanType::MESH_BOOLEAN_TYPE_MINUS,
 												outputMeshVerts, outputMeshCells);
 		}
-		else if (this->Mode == Modes::DIFFERENCE2)
+		else if (this->Mode == stkLibiglBoolean3DMesher::Modes::DIFFERENCE2)
 		{
 			igl::copyleft::cgal::mesh_boolean(inputMeshBVerts, inputMeshBCells,
 												inputMeshAVerts, inputMeshACells,
diff --git a/Plugins/Libigl/stkLibiglCopyleft/stkLibiglBoolean3DMesher.h b/Plugins/Libigl/stkLibiglCopyleft/stkLibiglBoolean3DMesher.h
index 71f0ec8..76a5ad0 100644
--- a/Plugins/Libigl/stkLibiglCopyleft/stkLibiglBoolean3DMesher.h
+++ b/Plugins/Libigl/stkLibiglCopyleft/stkLibiglBoolean3DMesher.h
@@ -18,7 +18,7 @@ class STKLIBIGLCOPYLEFT_EXPORT stkLibiglBoolean3DMesher : public vtkPolyDataAlgo
   vtkPolyData* GetInputMeshB();
 
   enum Modes {
-      UNION = 0,
+      UNION = 1,
       INTERSECTION,
       DIFFERENCE,
       DIFFERENCE2
diff --git a/Plugins/Libigl/stkLibiglCopyleft/stkLibiglCopyleftPlugins.xml b/Plugins/Libigl/stkLibiglCopyleft/stkLibiglCopyleftPlugins.xml
index 0257902..7285faa 100644
--- a/Plugins/Libigl/stkLibiglCopyleft/stkLibiglCopyleftPlugins.xml
+++ b/Plugins/Libigl/stkLibiglCopyleft/stkLibiglCopyleftPlugins.xml
@@ -24,10 +24,10 @@
 
             <IntVectorProperty name="Mode" command="SetMode" number_of_elements="1" default_values="0">
                 <EnumerationDomain name="enum">
-                    <Entry value="0" text="Union"/>
-                    <Entry value="1" text="Intersection"/>
-                    <Entry value="2" text="Difference"/>
-                    <Entry value="3" text="Difference2"/>
+                    <Entry value="1" text="Union"/>
+                    <Entry value="2" text="Intersection"/>
+                    <Entry value="3" text="Difference"/>
+                    <Entry value="4" text="Difference2"/>
                 </EnumerationDomain>
                 <Documentation>
                     Set the boolean operation to perform.