diff --git a/src/java/mmm/materials/MWood.java b/src/java/mmm/materials/MWood.java
index 57376c1..16199e9 100644
--- a/src/java/mmm/materials/MWood.java
+++ b/src/java/mmm/materials/MWood.java
@@ -5,6 +5,7 @@ import java.util.Random;
 
 import mmm.utils.I_URecipeRegistrar;
 import mmm.utils.URegistry;
+import mmm.world.trees.A_MTreeGenerator;
 import net.minecraft.block.Block;
 import net.minecraft.block.material.MapColor;
 import net.minecraft.block.state.IBlockState;
diff --git a/src/java/mmm/materials/Materials.java b/src/java/mmm/materials/Materials.java
index e281bcd..a91bb4d 100644
--- a/src/java/mmm/materials/Materials.java
+++ b/src/java/mmm/materials/Materials.java
@@ -10,6 +10,7 @@ import mmm.world.WLocation;
 import mmm.world.WLocationInBiome;
 import mmm.world.gen.WGOreCondition;
 import mmm.world.gen.WGOreParameters;
+import mmm.world.trees.MHeveaGenerator;
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockStone;
 import net.minecraft.block.material.MapColor;
diff --git a/src/java/mmm/materials/A_MTreeGenerator.java b/src/java/mmm/world/trees/A_MTreeGenerator.java
similarity index 98%
rename from src/java/mmm/materials/A_MTreeGenerator.java
rename to src/java/mmm/world/trees/A_MTreeGenerator.java
index 5b2f2ef..2044467 100644
--- a/src/java/mmm/materials/A_MTreeGenerator.java
+++ b/src/java/mmm/world/trees/A_MTreeGenerator.java
@@ -1,8 +1,9 @@
-package mmm.materials;
+package mmm.world.trees;
 
 
 import java.util.Random;
 
+import mmm.materials.MWood;
 import net.minecraft.block.Block;
 import net.minecraft.block.material.Material;
 import net.minecraft.block.state.IBlockState;
@@ -140,7 +141,7 @@ public abstract class A_MTreeGenerator
 	}
 
 
-	void setWood( final MWood wood )
+	public void setWood( final MWood wood )
 	{
 		this.wood = wood;
 	}
diff --git a/src/java/mmm/materials/MHeveaGenerator.java b/src/java/mmm/world/trees/MHeveaGenerator.java
similarity index 97%
rename from src/java/mmm/materials/MHeveaGenerator.java
rename to src/java/mmm/world/trees/MHeveaGenerator.java
index 2bbfc69..0d90fbe 100644
--- a/src/java/mmm/materials/MHeveaGenerator.java
+++ b/src/java/mmm/world/trees/MHeveaGenerator.java
@@ -1,8 +1,9 @@
-package mmm.materials;
+package mmm.world.trees;
 
 
 import java.util.Random;
 
+import mmm.materials.MLeaves;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.util.math.BlockPos;