diff --git a/Project.toml b/Project.toml
index dc80aa5bd..09197f7ae 100644
--- a/Project.toml
+++ b/Project.toml
@@ -15,7 +15,7 @@ Setfield = "efcf1570-3423-57d1-acb7-fd33fddbac46"
 Transducers = "28d57a85-8fef-5791-bfe6-a80928e7c999"
 
 [compat]
-BangBang = "0.3.34"
+BangBang = "0.3.34, 0.4"
 Compat = "2.1, 3.0, 4"
 FLoopsBase = "0.1.1"
 InitialValues = "0.3.1"