diff --git a/packages/store/src/StoreCore.sol b/packages/store/src/StoreCore.sol
index 696bb399f6..5784ade397 100644
--- a/packages/store/src/StoreCore.sol
+++ b/packages/store/src/StoreCore.sol
@@ -1003,8 +1003,8 @@ library StoreCoreInternal {
     }
 
     // The start index can't be larger than the previous length of the field
-    if (startWithinField > previousFieldLength) {
-      revert IStoreErrors.Store_IndexOutOfBounds(previousFieldLength, startWithinField);
+    if (startWithinField > previousFieldLength - deleteCount) {
+      revert IStoreErrors.Store_IndexOutOfBounds(previousFieldLength - deleteCount, startWithinField);
     }
 
     // Update the encoded length
diff --git a/packages/store/test/StoreCore.t.sol b/packages/store/test/StoreCore.t.sol
index 27a38b54cd..893ec22b73 100644
--- a/packages/store/test/StoreCore.t.sol
+++ b/packages/store/test/StoreCore.t.sol
@@ -1023,7 +1023,7 @@ contract StoreCoreTest is Test, StoreMock {
     vm.expectRevert(
       abi.encodeWithSelector(
         IStoreErrors.Store_IndexOutOfBounds.selector,
-        data.newThirdDataBytes.length,
+        data.newThirdDataBytes.length - uint40(data.thirdDataForUpdate.length),
         uint40(type(uint56).max)
       )
     );
@@ -1035,6 +1035,23 @@ contract StoreCoreTest is Test, StoreMock {
       uint40(data.thirdDataForUpdate.length),
       data.thirdDataForUpdate
     );
+
+    // startByteIndex + deleteCount must not overflow
+    vm.expectRevert(
+      abi.encodeWithSelector(
+        IStoreErrors.Store_IndexOutOfBounds.selector,
+        data.newThirdDataBytes.length - 8,
+        data.newThirdDataBytes.length
+      )
+    );
+    this.spliceDynamicData(
+      data.tableId,
+      data.keyTuple,
+      1,
+      uint40(data.newThirdDataBytes.length), // set start to end of the field
+      uint40(8), // delete 8 bytes (after the start index, so after the size of the field)
+      abi.encodePacked(uint64(1)) // append 8 bytes
+    );
   }
 
   function testAccessEmptyData() public {