diff --git a/Project.toml b/Project.toml
index 8c150ef..f6b0b93 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "SatelliteDynamics"
 uuid = "0e7c1a32-1b9f-5532-88a4-e668712d6a4c"
 authors = ["Duncan Eddy <duncan.eddy@gmail.com>"]
-version = "0.3.1"
+version = "0.4.0"
 
 [deps]
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"