diff --git a/src/main/java/dan200/computercraft/shared/turtle/core/TurtleMoveCommand.java b/src/main/java/dan200/computercraft/shared/turtle/core/TurtleMoveCommand.java
index cadc8b73ec..366e90d115 100644
--- a/src/main/java/dan200/computercraft/shared/turtle/core/TurtleMoveCommand.java
+++ b/src/main/java/dan200/computercraft/shared/turtle/core/TurtleMoveCommand.java
@@ -150,13 +150,9 @@ public TurtleCommandResult execute( @Nonnull ITurtleAccess turtle )
 
     private TurtleCommandResult canEnter( TurtlePlayer turtlePlayer, World world, BlockPos position )
     {
-        if( position.getY() < 0 )
+        if( world.isOutsideBuildHeight( position ) )
         {
-            return TurtleCommandResult.failure( "Too low to move" );
-        }
-        else if( position.getY() > world.getHeight() - 1 )
-        {
-            return TurtleCommandResult.failure( "Too high to move" );
+            return TurtleCommandResult.failure( "Move would be outside world height." );
         }
         if( ComputerCraft.turtlesObeyBlockProtection )
         {
diff --git a/src/main/java/dan200/computercraft/shared/util/InventoryUtil.java b/src/main/java/dan200/computercraft/shared/util/InventoryUtil.java
index f7e808a449..8a4daa1dff 100644
--- a/src/main/java/dan200/computercraft/shared/util/InventoryUtil.java
+++ b/src/main/java/dan200/computercraft/shared/util/InventoryUtil.java
@@ -49,8 +49,7 @@ public static ItemStack copyItem( @Nonnull ItemStack a )
     public static IItemHandler getInventory( World world, BlockPos pos, EnumFacing side )
     {
         // Look for tile with inventory
-        int y = pos.getY();
-        if( y >= 0 && y < world.getHeight() )
+        if( !world.isOutsideBuildHeight( pos ) )
         {
             TileEntity tileEntity = world.getTileEntity( pos );
             if( tileEntity != null )
diff --git a/src/main/java/dan200/computercraft/shared/util/WorldUtil.java b/src/main/java/dan200/computercraft/shared/util/WorldUtil.java
index ff7289a4df..a84483ff84 100644
--- a/src/main/java/dan200/computercraft/shared/util/WorldUtil.java
+++ b/src/main/java/dan200/computercraft/shared/util/WorldUtil.java
@@ -21,7 +21,7 @@ public class WorldUtil
 {
     public static boolean isBlockInWorld( World world, BlockPos pos )
     {
-        return pos.getY() >= 0 && pos.getY() < world.getHeight();
+        return !world.isOutsideBuildHeight( pos );
     }
 
     public static boolean isLiquidBlock( World world, BlockPos pos )