diff --git a/VTK/IO/vtkXMLWriter.cxx b/VTK/IO/vtkXMLWriter.cxx
index 88858f0..aa2a122 100644
--- a/VTK/IO/vtkXMLWriter.cxx
+++ b/VTK/IO/vtkXMLWriter.cxx
@@ -293,12 +293,13 @@ void vtkXMLWriter::SetCompressorType(int compressorType)
 
   if (compressorType == ZLIB)
     {
-    if (!this->Compressor || !this->Compressor->IsTypeOf("vtkZLibDataCompressor"))
+    if (this->Compressor && !this->Compressor->IsTypeOf("vtkZLibDataCompressor"))
       {
       this->Compressor->Delete();
+      }
+
       this->Compressor = vtkZLibDataCompressor::New();
       this->Modified();
-      }
     return;
     }
 }