diff --git a/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.h b/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.h
index b2d65475..696d21e1 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.h
+++ b/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.h
@@ -60,7 +60,7 @@ namespace PolyVox
 			return func;
 		}
 
-		const IsVoxelTransparentCallback& mIsVoxelTransparentCallback;
+		IsVoxelTransparentCallback mIsVoxelTransparentCallback;
 	};
 
 	// NOTE: The callback needs to be a functor not a function. I haven't been
@@ -74,7 +74,7 @@ namespace PolyVox
 	
 	/// Calculate the ambient occlusion for the volume
 	template<typename VolumeType, typename IsVoxelTransparentCallback>
-	void calculateAmbientOcclusion(VolumeType* volInput, Array<3, uint8_t>* arrayResult, Region region, float fRayLength, uint8_t uNoOfSamplesPerOutputElement, const IsVoxelTransparentCallback& isVoxelTransparentCallback);
+	void calculateAmbientOcclusion(VolumeType* volInput, Array<3, uint8_t>* arrayResult, Region region, float fRayLength, uint8_t uNoOfSamplesPerOutputElement, IsVoxelTransparentCallback isVoxelTransparentCallback);
 }
 
 #include "PolyVoxCore/AmbientOcclusionCalculator.inl"
diff --git a/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.inl b/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.inl
index 8659cadf..80184824 100644
--- a/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.inl
+++ b/library/PolyVoxCore/include/PolyVoxCore/AmbientOcclusionCalculator.inl
@@ -32,7 +32,7 @@ namespace PolyVox
 	 * \param isVoxelTransparentCallback A callback which takes a \a VoxelType and returns a \a bool whether the voxel is transparent
 	 */
 	template<typename VolumeType, typename IsVoxelTransparentCallback>
-	void calculateAmbientOcclusion(VolumeType* volInput, Array<3, uint8_t>* arrayResult, Region region, float fRayLength, uint8_t uNoOfSamplesPerOutputElement, const IsVoxelTransparentCallback& isVoxelTransparentCallback)
+	void calculateAmbientOcclusion(VolumeType* volInput, Array<3, uint8_t>* arrayResult, Region region, float fRayLength, uint8_t uNoOfSamplesPerOutputElement, IsVoxelTransparentCallback isVoxelTransparentCallback)
 	{
 		typename VolumeType::Sampler m_sampVolume(volInput);