diff --git a/Project.toml b/Project.toml
index c4936b855..7441116da 100644
--- a/Project.toml
+++ b/Project.toml
@@ -13,7 +13,7 @@ ReinforcementLearningZoo = "d607f57d-ee1e-4ba7-bcf2-7734c1e31854"
 [compat]
 Reexport = "0.2, 1"
 ReinforcementLearningBase = "0.9"
-ReinforcementLearningCore = "0.8"
+ReinforcementLearningCore = "0.8, 0.9"
 ReinforcementLearningEnvironments = "0.6"
 ReinforcementLearningZoo = "0.5"
 julia = "1.6"