1 files changed, 2 insertions, 2 deletions

diff --git a/src/undo.rs b/src/undo.rs
index 2249fe7..b590312 100644
--- a/src/undo.rs
+++ b/src/undo.rs
@@ -1,12 +1,12 @@
 #[derive(Copy, Clone, Debug)]
 pub struct ModifyRecord {
-    pub point: (i32, i32),
+    pub point: (u32, u32),
     pub old_val: bool,
     pub val: bool,
 }
 
 impl ModifyRecord {
-    pub fn new(point: (i32, i32), old_val: bool, val: bool) -> Self {
+    pub fn new(point: (u32, u32), old_val: bool, val: bool) -> Self {
         ModifyRecord {
             point,
             old_val,