diff --git a/src/ifcgeom/ConversionSettings.h b/src/ifcgeom/ConversionSettings.h
index eb405a9e7c..febd789f6b 100644
--- a/src/ifcgeom/ConversionSettings.h
+++ b/src/ifcgeom/ConversionSettings.h
@@ -452,6 +452,12 @@ namespace ifcopenshell {
 				static constexpr bool defaultvalue = false;
 			};
 
+			struct MakeVolume : public SettingBase<MakeVolume, bool> {
+                static constexpr const char* const name = "make-volume";
+                static constexpr const char* const description = "Try to isolate and fix a valid volume from non-manifold elements prior to opening subtraction";
+                static constexpr bool defaultvalue = false;
+            };
+
 			struct DeferProcessingFirstElement : public SettingBase<DeferProcessingFirstElement, bool, true> {
 				static constexpr const char* const name = "defer-processing-first-element";
 				static constexpr const char* const description = "Don't process first element in Iterator::initialize call()";
@@ -647,7 +653,7 @@ namespace ifcopenshell {
 		};
 
 		class Settings : public SettingsContainer<
-                             std::tuple<MesherLinearDeflection, MesherAngularDeflection, ReorientShells, LengthUnit, PlaneUnit, Precision, OutputDimensionality, LayersetFirst, DisableBooleanResult, NoWireIntersectionCheck, NoWireIntersectionTolerance, PrecisionFactor, DebugBooleanOperations, BooleanAttempt2d, SurfaceColour, WeldVertices, UseWorldCoords, UnifyShapes, UseMaterialNames, ConvertBackUnits, ContextIds, ContextTypes, ContextIdentifiers, IteratorOutput, DisableOpeningSubtractions, ApplyDefaultMaterials, DontEmitNormals, GenerateUvs, ApplyLayerSets, UseElementHierarchy, ValidateQuantities, EdgeArrows, BuildingLocalPlacement, SiteLocalPlacement, ForceSpaceTransparency, CircleSegments, CgalSmoothAngleDegrees, KeepBoundingBoxes, ComputeCurvature, FunctionStepType, FunctionStepParam, NoParallelMapping, PermissiveShapeReuse, ModelOffset, ModelRotation, TriangulationType, CgalEmitOriginalEdges, OcctNoCleanTriangulation, CacheShapes, DeferProcessingFirstElement, MaxOffset, MaxOffsetDeviation, ApplyOffset>
+                             std::tuple<MesherLinearDeflection, MesherAngularDeflection, ReorientShells, LengthUnit, PlaneUnit, Precision, OutputDimensionality, LayersetFirst, DisableBooleanResult, NoWireIntersectionCheck, NoWireIntersectionTolerance, PrecisionFactor, DebugBooleanOperations, BooleanAttempt2d, SurfaceColour, WeldVertices, UseWorldCoords, UnifyShapes, UseMaterialNames, ConvertBackUnits, ContextIds, ContextTypes, ContextIdentifiers, IteratorOutput, DisableOpeningSubtractions, ApplyDefaultMaterials, DontEmitNormals, GenerateUvs, ApplyLayerSets, UseElementHierarchy, ValidateQuantities, EdgeArrows, BuildingLocalPlacement, SiteLocalPlacement, ForceSpaceTransparency, CircleSegments, CgalSmoothAngleDegrees, KeepBoundingBoxes, ComputeCurvature, FunctionStepType, FunctionStepParam, NoParallelMapping, PermissiveShapeReuse, ModelOffset, ModelRotation, TriangulationType, CgalEmitOriginalEdges, OcctNoCleanTriangulation, CacheShapes, DeferProcessingFirstElement, MaxOffset, MaxOffsetDeviation, ApplyOffset, MakeVolume>
 		>
 		{};
 }
diff --git a/src/ifcgeom/kernels/opencascade/OpenCascadeKernel.cpp b/src/ifcgeom/kernels/opencascade/OpenCascadeKernel.cpp
index fcb390b6cc..a5a9d94149 100644
--- a/src/ifcgeom/kernels/opencascade/OpenCascadeKernel.cpp
+++ b/src/ifcgeom/kernels/opencascade/OpenCascadeKernel.cpp
@@ -29,6 +29,7 @@
 #include "base_utils.h"
 
 #include <BRepPrimAPI_MakeRevol.hxx>
+#include <BOPAlgo_MakerVolume.hxx>
 
 namespace {
 	struct opening_sorter {
@@ -132,11 +133,24 @@ bool IfcGeom::OpenCascadeKernel::convert_openings(const IfcUtil::IfcBaseEntity*
 			parts.push_back(it3_shape);
 		}
 
-		for (auto& entity_part : parts) {
+		for (auto entity_part : parts) {
 			bool is_manifold = util::is_manifold(entity_part);
 
 			if (!is_manifold) {
-				Logger::Warning("Non-manifold first operand");
+                if (settings_.get<settings::MakeVolume>().get()) {
+                    BOPAlgo_MakerVolume mv;
+                    mv.AddArgument(entity_part);
+                    mv.SetAvoidInternalShapes(true);
+                    try {
+                        mv.Perform();
+                        entity_part = mv.Shape();
+                        Logger::Warning("Sucessfully detected exterior volume to non-manifold first operand");
+                    } catch (const Standard_Failure& e) {
+						Logger::Warning("MakeVolume failed: " + std::string(e.GetMessageString()), entity);
+                    }
+                } else {
+                    Logger::Warning("Non-manifold first operand, use --make-volume to try and make manifold");
+				}
 			}
 
 			TopoDS_Shape entity_part_result;