diff --git a/Project.toml b/Project.toml
index 9405f71a..73bca293 100644
--- a/Project.toml
+++ b/Project.toml
@@ -23,7 +23,7 @@ Convex = "0.14.16"
 HDF5 = "0.13.1, 0.14, 0.15"
 ITensors = "0.1.41, 0.2"
 JLD2 = "0.4.14"
-Observers = ">=0.0.3"
+Observers = "0.0.4"
 Optimisers = "0.1.0"
 SCS = "0.7.1"
 StatsBase = "0.33"