diff --git a/src/map.cpp b/src/map.cpp
index 1af8684e1..240788944 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -766,7 +766,7 @@ void MMVManip::initialEmerge(v3s16 blockpos_min, v3s16 blockpos_max,
 	VoxelArea block_area_nodes
 			(p_min*MAP_BLOCKSIZE, (p_max+1)*MAP_BLOCKSIZE-v3s16(1,1,1));
 
-	u32 size_MB = block_area_nodes.getVolume()*4/1000000;
+	u32 size_MB = block_area_nodes.getVolume() * sizeof(MapNode) / 1000000U;
 	if(size_MB >= 1)
 	{
 		infostream<<"initialEmerge: area: ";
@@ -855,7 +855,7 @@ MMVManip *MMVManip::clone() const
 {
 	MMVManip *ret = new MMVManip();
 
-	const s32 size = m_area.getVolume();
+	const u32 size = m_area.getVolume();
 	ret->m_area = m_area;
 	if (m_data) {
 		ret->m_data = new MapNode[size];
diff --git a/src/mapgen/treegen.cpp b/src/mapgen/treegen.cpp
index 688833fa2..8198cf266 100644
--- a/src/mapgen/treegen.cpp
+++ b/src/mapgen/treegen.cpp
@@ -77,7 +77,7 @@ void make_tree(MMVManip &vmanip, v3s16 p0, bool is_apple_tree,
 
 	VoxelArea leaves_a(v3s16(-2, -1, -2), v3s16(2, 2, 2));
 	Buffer<u8> leaves_d(leaves_a.getVolume());
-	for (s32 i = 0; i < leaves_a.getVolume(); i++)
+	for (u32 i = 0; i < leaves_d.getSize(); i++)
 		leaves_d[i] = 0;
 
 	// Force leaves at near the end of the trunk
@@ -697,9 +697,8 @@ void make_jungletree(MMVManip &vmanip, v3s16 p0, const NodeDefManager *ndef,
 	p1.Y -= 1;
 
 	VoxelArea leaves_a(v3s16(-3, -2, -3), v3s16(3, 2, 3));
-	//SharedPtr<u8> leaves_d(new u8[leaves_a.getVolume()]);
 	Buffer<u8> leaves_d(leaves_a.getVolume());
-	for (s32 i = 0; i < leaves_a.getVolume(); i++)
+	for (u32 i = 0; i < leaves_d.getSize(); i++)
 		leaves_d[i] = 0;
 
 	// Force leaves at near the end of the trunk
@@ -788,7 +787,7 @@ void make_pine_tree(MMVManip &vmanip, v3s16 p0, const NodeDefManager *ndef,
 
 	VoxelArea leaves_a(v3s16(-3, -6, -3), v3s16(3, 3, 3));
 	Buffer<u8> leaves_d(leaves_a.getVolume());
-	for (s32 i = 0; i < leaves_a.getVolume(); i++)
+	for (u32 i = 0; i < leaves_d.getSize(); i++)
 		leaves_d[i] = 0;
 
 	// Upper branches
diff --git a/src/unittest/test_voxelalgorithms.cpp b/src/unittest/test_voxelalgorithms.cpp
index 2a98412b4..b8ba11248 100644
--- a/src/unittest/test_voxelalgorithms.cpp
+++ b/src/unittest/test_voxelalgorithms.cpp
@@ -98,8 +98,8 @@ void TestVoxelAlgorithms::testLighting(IGameDef *gamedef)
 		std::map<v3s16, MapBlock*> modified_blocks;
 		MMVManip vm(&map);
 		vm.initialEmerge(bpmin, bpmax, false);
-		s32 volume = vm.m_area.getVolume();
-		for (s32 i = 0; i < volume; i++)
+		u32 volume = vm.m_area.getVolume();
+		for (u32 i = 0; i < volume; i++)
 			vm.m_data[i] = MapNode(CONTENT_AIR);
 		for (s16 z = -10; z <= 10; z++)
 		for (s16 y = -10; y <= 10; y++)
diff --git a/src/unittest/test_voxelarea.cpp b/src/unittest/test_voxelarea.cpp
index 321420a52..f594a9be7 100644
--- a/src/unittest/test_voxelarea.cpp
+++ b/src/unittest/test_voxelarea.cpp
@@ -124,16 +124,17 @@ void TestVoxelArea::test_extent()
 void TestVoxelArea::test_volume()
 {
 	VoxelArea v1(v3s16(-1337, -547, -789), v3s16(-147, 447, 669));
-	UASSERTEQ(s32, v1.getVolume(), 1728980655);
+	UASSERTEQ(u32, v1.getVolume(), 1728980655);
 
 	VoxelArea v2(v3s16(32493, -32507, 32752), v3s16(32508, -32492, 32767));
-	UASSERTEQ(s32, v2.getVolume(), 4096);
+	UASSERTEQ(u32, v2.getVolume(), 4096);
 
-	VoxelArea v3({-20000, 12, 34}, {20000, 12, 34});
-	UASSERTEQ(s32, v3.getVolume(), 40000);
+	// volume bigger than S32_MAX
+	VoxelArea v3({1, 1, 1}, {1337, 1337, 1337});
+	UASSERTEQ(u32, v3.getVolume(), 2389979753U);
 
-	UASSERTEQ(s32, VoxelArea({2,3,4}, {1,2,3}).getVolume(), 0);
-	UASSERTEQ(s32, VoxelArea({2,3,4}, {2,2,3}).getVolume(), 0);
+	UASSERTEQ(u32, VoxelArea({2,3,4}, {1,2,3}).getVolume(), 0);
+	UASSERTEQ(u32, VoxelArea({2,3,4}, {2,2,3}).getVolume(), 0);
 }
 
 void TestVoxelArea::test_contains_voxelarea()
diff --git a/src/voxel.cpp b/src/voxel.cpp
index d9fceb2b9..8f3858a1f 100644
--- a/src/voxel.cpp
+++ b/src/voxel.cpp
@@ -137,7 +137,7 @@ void VoxelManipulator::addArea(const VoxelArea &area)
 		new_area.addArea(area);
 	}
 
-	s32 new_size = new_area.getVolume();
+	u32 new_size = new_area.getVolume();
 
 	// Allocate new data and clear flags
 	MapNode *new_data = new MapNode[new_size];
@@ -147,7 +147,7 @@ void VoxelManipulator::addArea(const VoxelArea &area)
 	memset(new_flags, VOXELFLAG_NO_DATA, new_size);
 
 	// Copy old data
-	s32 old_x_width = m_area.MaxEdge.X - m_area.MinEdge.X + 1;
+	u32 old_x_width = m_area.getExtent().X;
 	for(s32 z=m_area.MinEdge.Z; z<=m_area.MaxEdge.Z; z++)
 	for(s32 y=m_area.MinEdge.Y; y<=m_area.MaxEdge.Y; y++)
 	{
diff --git a/src/voxel.h b/src/voxel.h
index a5ffc7ce6..a35be3e19 100644
--- a/src/voxel.h
+++ b/src/voxel.h
@@ -119,10 +119,10 @@ public:
 		return !m_cache_extent.X || !m_cache_extent.Y || !m_cache_extent.Z;
 	}
 
-	s32 getVolume() const
+	u32 getVolume() const
 	{
 		// FIXME: possible integer overflow here
-		return m_cache_extent.X * m_cache_extent.Y * m_cache_extent.Z;
+		return (u32)m_cache_extent.X * (u32)m_cache_extent.Y * (u32)m_cache_extent.Z;
 	}
 
 	bool contains(const VoxelArea &a) const
@@ -148,8 +148,9 @@ public:
 	}
 	bool contains(s32 i) const
 	{
-		return (i >= 0 && i < getVolume());
+		return i >= 0 && static_cast<u32>(i) < getVolume();
 	}
+
 	bool operator==(const VoxelArea &other) const
 	{
 		return (MinEdge == other.MinEdge