diff --git a/mine.lua b/mine.lua
index 4957b6c..b2b46d8 100644
--- a/mine.lua
+++ b/mine.lua
@@ -252,15 +252,17 @@ function mine (block)
     local offset = 1
     if block.v2.y < 0 then offset = -1 end
     local height = block.v2.y + offset
+    local start_v = copy_v(block.v1)
+    local end_v = block.v1 + block.v2
     if height % 3 == 0 then
         mode.mine = { up = true, forward = true, down = true }
     elseif height == 2 then
         mode.mine = { forward = true, up = true }
+        end_v = end_v - UNIT_Y
     elseif height == -2 then
         mode.mine = { forward = true, down = true }
+        end_v = end_v + UNIT_Y
     end
-    local start_v = copy_v(block.v1)
-    local end_v = block.v1 + block.v2
     if height > 2 then
         start_v = start_v + UNIT_Y
         end_v = end_v - UNIT_Y