diff --git a/corelib/src/util3d_filtering.cpp b/corelib/src/util3d_filtering.cpp
index dafe7dbedc..34b1491645 100644
--- a/corelib/src/util3d_filtering.cpp
+++ b/corelib/src/util3d_filtering.cpp
@@ -2155,7 +2155,7 @@ pcl::IndicesPtr normalFilteringImpl(
 		for(unsigned int i=0; i<cloud_normals->size(); ++i)
 		{
 			Eigen::Vector4f v(cloud_normals->at(i).normal_x, cloud_normals->at(i).normal_y, cloud_normals->at(i).normal_z, 0.0f);
-			if(groundNormalsUp>0.0f && v[2] < -groundNormalsUp && cloud->at(indices->size()!=0?indices->at(i):i).z < viewpoint[3]) // some far velodyne rays on road can have normals toward ground
+			if(groundNormalsUp>0.0f && v[2] < -groundNormalsUp && cloud->at(indices->size()!=0?indices->at(i):i).z < viewpoint[2]) // some far velodyne rays on road can have normals toward ground
 			{
 				//reverse normal
 				v *= -1.0f;
@@ -2226,7 +2226,7 @@ pcl::IndicesPtr normalFilteringImpl(
 			for(unsigned int i=0; i<indices->size(); ++i)
 			{
 				Eigen::Vector4f v(cloud->at(indices->at(i)).normal_x, cloud->at(indices->at(i)).normal_y, cloud->at(indices->at(i)).normal_z, 0.0f);
-				if(groundNormalsUp>0.0f && v[2] < -groundNormalsUp && cloud->at(indices->at(i)).z < viewpoint[3]) // some far velodyne rays on road can have normals toward ground
+				if(groundNormalsUp>0.0f && v[2] < -groundNormalsUp && cloud->at(indices->at(i)).z < viewpoint[2]) // some far velodyne rays on road can have normals toward ground
 				{
 					//reverse normal
 					v *= -1.0f;
@@ -2244,7 +2244,7 @@ pcl::IndicesPtr normalFilteringImpl(
 			for(unsigned int i=0; i<cloud->size(); ++i)
 			{
 				Eigen::Vector4f v(cloud->at(i).normal_x, cloud->at(i).normal_y, cloud->at(i).normal_z, 0.0f);
-				if(groundNormalsUp>0.0f && v[2] < -groundNormalsUp && cloud->at(i).z < viewpoint[3]) // some far velodyne rays on road can have normals toward ground
+				if(groundNormalsUp>0.0f && v[2] < -groundNormalsUp && cloud->at(i).z < viewpoint[2]) // some far velodyne rays on road can have normals toward ground
 				{
 					//reverse normal
 					v *= -1.0f;
diff --git a/corelib/src/util3d_surface.cpp b/corelib/src/util3d_surface.cpp
index c436f78d6f..1a50258ee6 100644
--- a/corelib/src/util3d_surface.cpp
+++ b/corelib/src/util3d_surface.cpp
@@ -3530,7 +3530,7 @@ LaserScan adjustNormalsToViewPoint(
 
 					float result = v.dot(n);
 					if(result < 0
-					 || (groundNormalsUp>0.0f && ptr[nz] < -groundNormalsUp && ptr[2] < viewpoint[3])) // some far velodyne rays on road can have normals toward ground
+					 || (groundNormalsUp>0.0f && ptr[nz] < -groundNormalsUp && ptr[2] < viewpoint[2])) // some far velodyne rays on road can have normals toward ground
 					{
 						//reverse normal
 						ptr[nx] *= -1.0f;
@@ -3569,7 +3569,7 @@ void adjustNormalsToViewPointImpl(
 
 			float result = v.dot(n);
 			if(result < 0
-				|| (groundNormalsUp>0.0f && normal.z < -groundNormalsUp && cloud->points[i].z < viewpoint[3])) // some far velodyne rays on road can have normals toward ground
+				|| (groundNormalsUp>0.0f && normal.z < -groundNormalsUp && cloud->points[i].z < viewpoint[2])) // some far velodyne rays on road can have normals toward ground
 			{
 				//reverse normal
 				cloud->points[i].normal_x *= -1.0f;