diff --git a/src/GEOMImpl/GEOMImpl_IBooleanOperations.cxx b/src/GEOMImpl/GEOMImpl_IBooleanOperations.cxx
index 8c71c551c..f6a022bb5 100644
--- a/src/GEOMImpl/GEOMImpl_IBooleanOperations.cxx
+++ b/src/GEOMImpl/GEOMImpl_IBooleanOperations.cxx
@@ -251,6 +251,7 @@ Handle(GEOM_Object) GEOMImpl_IBooleanOperations::MakePartition
     if (theMaterials.IsNull()) {
       Handle(TColStd_HArray1OfInteger) aMaterials =
         new TColStd_HArray1OfInteger (1, aShapesSeq->Length());
+      aMaterials->Init(0);
       aCI.SetMaterials(aMaterials);
     } else {
       aCI.SetMaterials(theMaterials);