diff --git a/src/mapgen.cpp b/src/mapgen.cpp
index 77b13302..782f00b6 100644
--- a/src/mapgen.cpp
+++ b/src/mapgen.cpp
@@ -132,7 +132,8 @@ void make_tree(ManualMapVoxelManipulator &vmanip, v3s16 p0,
 	for(s16 ii=0; ii<trunk_h; ii++)
 	{
 		if(vmanip.m_area.contains(p1))
-			vmanip.m_data[vmanip.m_area.index(p1)] = treenode;
+			if(ii == 0 || vmanip.getNodeNoExNoEmerge(p1).getContent() == CONTENT_AIR)
+				vmanip.m_data[vmanip.m_area.index(p1)] = treenode;
 		p1.Y++;
 	}