diff --git a/library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.h b/library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.h
index 716f4336..5074a92c 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.h
+++ b/library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.h
@@ -24,7 +24,7 @@ freely, subject to the following restrictions:
 #ifndef __PolyVox_VolumeResampler_H__
 #define __PolyVox_VolumeResampler_H__
 
-#include <cmath>
+#include "PolyVoxCore/Region.h"
 
 namespace PolyVox
 {
@@ -32,7 +32,7 @@ namespace PolyVox
 	class VolumeResampler
 	{
 	public:
-		VolumeResampler(SrcVolumeType* pVolSrc, Region regSrc, DstVolumeType* pVolDst, Region regDst);
+		VolumeResampler(SrcVolumeType* pVolSrc, const Region& regSrc, DstVolumeType* pVolDst, const Region& regDst);
 
 		void execute();
 
diff --git a/library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.inl b/library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.inl
index 8469c1d3..67db5c1e 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.inl
+++ b/library/PolyVoxCore/include/PolyVoxCore/VolumeResampler.inl
@@ -23,6 +23,8 @@ freely, subject to the following restrictions:
 
 #include "PolyVoxCore/Interpolation.h"
 
+#include <cmath>
+
 namespace PolyVox
 {
 	/**
@@ -32,7 +34,7 @@ namespace PolyVox
 	 * \param regDst
 	 */
 	template< typename SrcVolumeType, typename DstVolumeType>
-	VolumeResampler<SrcVolumeType, DstVolumeType>::VolumeResampler(SrcVolumeType* pVolSrc, Region regSrc, DstVolumeType* pVolDst, Region regDst)
+	VolumeResampler<SrcVolumeType, DstVolumeType>::VolumeResampler(SrcVolumeType* pVolSrc, const Region &regSrc, DstVolumeType* pVolDst, const Region& regDst)
 		:m_pVolSrc(pVolSrc)
 		,m_regSrc(regSrc)
 		,m_pVolDst(pVolDst)