diff --git a/README.md b/README.md
index 3e0f39a..01aad33 100644
--- a/README.md
+++ b/README.md
@@ -13,9 +13,9 @@ local c_stone = minetest.get_content_id("default:stone")
 local c_water = minetest.get_content_id("default:water_source")
 local water_level = 0
 local old_logic = luamap.logic
-function luamap.logic(noise_vals,x,y,z,seed)
+function luamap.logic(noise_vals,x,y,z,seed,original_content)
     -- get any terrain defined in another mod
-    local content = old_logic(noise_vals,x,y,z,seed)
+    local content = old_logic(noise_vals,x,y,z,seed,original_content)
     -- use our own logic to add to that logic 
     -- make any nodes below sea level water and below stone level stone
     if y < water_level then
@@ -54,9 +54,9 @@ local c_stone = minetest.get_content_id("default:stone")
 local c_water = minetest.get_content_id("default:water_source")
 local water_level = 0
 local old_logic = luamap.logic
-function luamap.logic(noise_vals,x,y,z,seed)
+function luamap.logic(noise_vals,x,y,z,seed,original_content)
     -- get any terrain defined in another mod
-    local content = old_logic(noise_vals,x,y,z,seed)
+    local content = old_logic(noise_vals,x,y,z,seed,original_content)
 
     if y < water_level then
         content = c_water
@@ -92,7 +92,7 @@ luamap.register_noise("terrainmap",{
 
 ### luamap.logic
 ```lua
-luamap.logic(noise_vals,x,y,z,seed)
+luamap.logic(noise_vals,x,y,z,seed,original_content)
 ```
 
 DESCRIPTION: Override this function to define mapgen logic. Best practice is to
@@ -121,6 +121,10 @@ The coordinates of the position to set the content for
 
 The seed passed to minetest.register_on_generated()
 
+`original_content`
+
+The original content of the mapgen
+
 RETURNS:
 
 should return a content id such as that gotten from
diff --git a/example.lua b/example.lua
index 46333f0..73c4f2d 100644
--- a/example.lua
+++ b/example.lua
@@ -26,10 +26,10 @@ local water_level = 0
 
 local old_logic = luamap.logic
 
-function luamap.logic(noise_vals,x,y,z,seed)
+function luamap.logic(noise_vals,x,y,z,seed,original_content)
 
     -- get any terrain defined in another mod
-    local content = old_logic(noise_vals,x,y,z,seed)
+    local content = old_logic(noise_vals,x,y,z,seed,original_content)
 
     if y < water_level then
         content = c_water