diff --git a/package.json b/package.json
index 38262d83c..e01980c4d 100644
--- a/package.json
+++ b/package.json
@@ -85,7 +85,7 @@
     "@sabaki/go-board": "^1.4.1",
     "@sabaki/gtp": "^3.0.0",
     "@sabaki/i18n": "0.50.1-1",
-    "@sabaki/immutable-gametree": "^1.8.2",
+    "@sabaki/immutable-gametree": "^1.9.1",
     "@sabaki/influence": "^1.2.2",
     "@sabaki/sgf": "^3.4.7",
     "@sabaki/shudan": "^1.5.4",
@@ -110,7 +110,7 @@
     "electron": "^8.1.1",
     "electron-builder": "^22.4.1",
     "esm": "^3.2.25",
-    "mocha": "^7.1.0",
+    "mocha": "^7.1.1",
     "onchange": "^6.1.0",
     "prettier": "1.19.1",
     "react": "^16.13.0",
diff --git a/src/modules/gametree.js b/src/modules/gametree.js
index f803d691f..5d4e4ae32 100644
--- a/src/modules/gametree.js
+++ b/src/modules/gametree.js
@@ -385,7 +385,3 @@ export function getBoard(tree, id) {
 export function clearBoardCache() {
   boardCache = {}
 }
-
-export function getHash(tree) {
-  return helper.hash(JSON.stringify(tree))
-}
diff --git a/src/modules/sabaki.js b/src/modules/sabaki.js
index 1f0dabd0d..e3b5b3792 100644
--- a/src/modules/sabaki.js
+++ b/src/modules/sabaki.js
@@ -748,7 +748,7 @@ class Sabaki extends EventEmitter {
   }
 
   generateTreeHash() {
-    return this.state.gameTrees.map(tree => gametree.getHash(tree)).join('-')
+    return this.state.gameTrees.map(tree => tree.getHash()).join('-')
   }
 
   generateFileHash() {