diff --git a/Project.toml b/Project.toml
index 36a8c43..c6adebb 100644
--- a/Project.toml
+++ b/Project.toml
@@ -26,7 +26,7 @@ EllipsisNotation = "1"
 FastMPOContractions = "^0.2.2"
 ITensorMPS = "0.3.1"
 ITensors = "0.7"
-PartitionedMPSs = "0.5.2"
+PartitionedMPSs = "0.5.2, 0.6"
 QuanticsTCI = "0.7"
 SparseIR = "^0.96, 0.97, 1"
 StaticArrays = "1"