diff --git a/gillespy2/__version__.py b/gillespy2/__version__.py
index 1dacea00f..30d5899df 100644
--- a/gillespy2/__version__.py
+++ b/gillespy2/__version__.py
@@ -24,7 +24,7 @@
 # =============================================================================
 
 
-__version__      = '1.6.3'
+__version__      = '1.6.4'
 
 __title__        = 'GillesPy2'
 __description__  = 'Python interface for Gillespie-style biochemical simulations'