diff --git a/package.json b/package.json
index 69472c87..f0f3cb44 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,7 @@
     "lint": "standard && tsc",
     "docs": "rm -rf docs; jsdoc --configure ./.jsdoc.json --verbose --readme ./README.v13.md --package ./package.json || true",
     "serve-docs": "npm run docs && serve ./docs/",
-    "preversion": "PRODUCTION=1 npm run dist && node ./dist/tests.js --repitition-time 10000",
+    "preversion": "PRODUCTION=1 npm run dist && node ./dist/tests.js --repitition-time 1000",
     "postversion": "git push && git push --tags",
     "debug": "concurrently 'live-server --port=3443 --entry-file=test.html' 'npm run watch'",
     "trace-deopt": "clear && rollup -c  && node --trace-deopt dist/test.js",
diff --git a/src/structs/AbstractItem.js b/src/structs/AbstractItem.js
index ace332df..614fb4ef 100644
--- a/src/structs/AbstractItem.js
+++ b/src/structs/AbstractItem.js
@@ -76,6 +76,10 @@ export const splitItem = (transaction, leftItem, diff) => {
   }
   // right is more specific.
   transaction._mergeStructs.add(rightItem.id)
+  // update parent._map
+  if (rightItem.parentSub !== null && rightItem.right === null) {
+    rightItem.parent._map.set(rightItem.parentSub, rightItem)
+  }
   return rightItem
 }
 
@@ -426,7 +430,7 @@ export class AbstractItem extends AbstractStruct {
    * @private
    */
   gc (transaction, store, parentGCd) {
-    this.delete(transaction)
+    this.delete(transaction) // @todo: shouldn't be necessary
     let r
     if (parentGCd) {
       r = new GC(this.id, this.length)
@@ -612,7 +616,9 @@ export const computeItemParams = (transaction, store, leftid, rightid, parentid,
       case GC:
         break
       default:
-        parent = parentItem.type
+        if (!parentItem.deleted) {
+          parent = parentItem.type
+        }
     }
   } else if (parentYKey !== null) {
     parent = transaction.y.get(parentYKey)
diff --git a/tests/testHelper.js b/tests/testHelper.js
index 54dd1172..3ea840da 100644
--- a/tests/testHelper.js
+++ b/tests/testHelper.js
@@ -9,7 +9,6 @@ import {
 
 import * as t from 'lib0/testing.js'
 import * as prng from 'lib0/prng.js'
-import { createMutex } from 'lib0/mutex.js'
 import * as encoding from 'lib0/encoding.js'
 import * as decoding from 'lib0/decoding.js'
 import * as syncProtocol from 'y-protocols/sync.js'
diff --git a/tests/y-array.tests.js b/tests/y-array.tests.js
index ec3d3f07..ffa595f8 100644
--- a/tests/y-array.tests.js
+++ b/tests/y-array.tests.js
@@ -335,8 +335,8 @@ const arrayTransactions = [
 /**
  * @param {t.TestCase} tc
  */
-export const testRepeatGeneratingYarrayTests20 = tc => {
-  applyRandomTests(tc, arrayTransactions, 3)
+export const testRepeatGeneratingYarrayTests4 = tc => {
+  applyRandomTests(tc, arrayTransactions, 4)
 }
 
 /**