diff --git a/mods/default/mapgen.lua b/mods/default/mapgen.lua
index a12fe580..1a85bf30 100644
--- a/mods/default/mapgen.lua
+++ b/mods/default/mapgen.lua
@@ -1033,7 +1033,7 @@ function default.register_biomes(upper_limit)
 		--node_river_water = "",
 		node_riverbed = "default:sand",
 		depth_riverbed = 2,
-		y_min = 5,
+		y_min = 4,
 		y_max = 5,
 		heat_point = 50,
 		humidity_point = 35,
@@ -1054,7 +1054,7 @@ function default.register_biomes(upper_limit)
 		node_riverbed = "default:sand",
 		depth_riverbed = 2,
 		y_min = -112,
-		y_max = 4,
+		y_max = 3,
 		heat_point = 50,
 		humidity_point = 35,
 	})
@@ -1095,7 +1095,7 @@ function default.register_biomes(upper_limit)
 		--node_river_water = "",
 		node_riverbed = "default:sand",
 		depth_riverbed = 2,
-		y_min = 5,
+		y_min = 4,
 		y_max = 5,
 		heat_point = 45,
 		humidity_point = 70,
@@ -1116,7 +1116,7 @@ function default.register_biomes(upper_limit)
 		node_riverbed = "default:sand",
 		depth_riverbed = 2,
 		y_min = -112,
-		y_max = 4,
+		y_max = 3,
 		heat_point = 45,
 		humidity_point = 70,
 	})