diff --git a/src/dungeongen.cpp b/src/dungeongen.cpp
index 5dc87f8b01e3..b8ee2b92471c 100644
--- a/src/dungeongen.cpp
+++ b/src/dungeongen.cpp
@@ -415,8 +415,8 @@ void DungeonGen::makeCorridor(v3s16 doorplace, v3s16 doordir,
 		if (partcount != 0)
 			p.Y += make_stairs;
 
-		if (vm->m_area.contains(p) && vm->m_area.contains(p + v3s16(0, 1, 0)) &&
-				vm->m_area.contains(v3s16(p.X - dir.X, p.Y - 1, p.Z - dir.Z))) {
+		// Check segment of minimum size corridor is in voxelmanip
+		if (vm->m_area.contains(p) && vm->m_area.contains(p + v3s16(0, 1, 0))) {
 			if (make_stairs) {
 				makeFill(p + v3s16(-1, -1, -1),
 					dp.holesize + v3s16(2, 3, 2),
@@ -444,11 +444,13 @@ void DungeonGen::makeCorridor(v3s16 doorplace, v3s16 doordir,
 
 					for (u16 st = 0; st < stair_width; st++) {
 						u32 vi = vm->m_area.index(ps.X - dir.X, ps.Y - 1, ps.Z - dir.Z);
-						if (vm->m_data[vi].getContent() == dp.c_wall)
+						if (vm->m_area.contains(ps + v3s16(-dir.X, -1, -dir.Z)) &&
+								vm->m_data[vi].getContent() == dp.c_wall)
 							vm->m_data[vi] = MapNode(dp.c_stair, 0, facedir);
 
 						vi = vm->m_area.index(ps.X, ps.Y, ps.Z);
-						if (vm->m_data[vi].getContent() == dp.c_wall)
+						if (vm->m_area.contains(ps) &&
+								vm->m_data[vi].getContent() == dp.c_wall)
 							vm->m_data[vi] = MapNode(dp.c_stair, 0, facedir);
 
 						ps += swv;