diff --git a/sgf/src/game.rs b/sgf/src/game.rs
index 68754e0..7ba5aed 100644
--- a/sgf/src/game.rs
+++ b/sgf/src/game.rs
@@ -1,17 +1,10 @@
 use crate::{
-    parser::{self, Annotation, Evaluation, UnknownProperty},
+    parser::{self, Annotation, Evaluation, SetupInstr, UnknownProperty},
     Color,
 };
 use std::{collections::HashSet, time::Duration};
 use uuid::Uuid;
 
-/*
-#[derive(Clone, Debug, PartialEq)]
-pub enum PropertyError {
-    ConflictingProperty,
-}
- */
-
 #[derive(Clone, Debug, PartialEq)]
 pub enum MoveNodeError {
     IncompatibleProperty,
@@ -222,19 +215,6 @@ impl TryFrom<&parser::Node> for MoveNode {
     }
 }
 
-/*
-fn parse_position(s: &str) -> Result<Position, ConversionError> {
-    if s.len() == 2 {
-        Ok(Position {
-            row: s[0],
-            column: s[1],
-        })
-    } else {
-        Err(ConversionError::InvalidPositionSyntax)
-    }
-}
-*/
-
 #[derive(Clone, Debug, PartialEq)]
 pub struct SetupNode {
     id: Uuid,
@@ -245,6 +225,18 @@ pub struct SetupNode {
 
 impl SetupNode {
     pub fn new(positions: Vec<parser::SetupInstr>) -> Result<Self, SetupNodeError> {
+        let mut board = HashSet::new();
+        for position in positions.iter() {
+            let point = match position {
+                SetupInstr::Piece((_, point)) => point,
+                SetupInstr::Clear(point) => point,
+            };
+            if board.contains(point) {
+                return Err(SetupNodeError::ConflictingPosition);
+            }
+            board.insert(point);
+        }
+
         Ok(Self {
             id: Uuid::new_v4(),
             positions,