-#if ITK_VERSION_MAJOR >= 4
-# if ITK_VERSION_MINOR < 6
- typedef itk::TransformToDisplacementFieldSource<OutputImageType, double> ConvertorType;
-# else
- typedef itk::TransformToDisplacementFieldFilter<OutputImageType, double> ConvertorType;
-# endif
+#if (ITK_VERSION_MAJOR == 4) && (ITK_VERSION_MINOR < 6)
+ typedef itk::TransformToDisplacementFieldSource<OutputImageType, double> ConvertorType;
+#else
+ typedef itk::TransformToDisplacementFieldFilter<OutputImageType, double> ConvertorType;