diff --git a/aerosandbox/__init__.py b/aerosandbox/__init__.py
index 094312d7..2b461afb 100644
--- a/aerosandbox/__init__.py
+++ b/aerosandbox/__init__.py
@@ -14,7 +14,7 @@
 from aerosandbox.propulsion import *
 from aerosandbox.structures import *
 
-__version__ = "4.2.0"
+__version__ = "4.2.1"
 
 
 def docs():