diff --git a/setup.py b/setup.py
index 0daafea..d06bc90 100644
--- a/setup.py
+++ b/setup.py
@@ -82,6 +82,7 @@
     'poppy>=1.1.0',
     'webbpsf>=1.3.0',
     'pysiaf>=0.22.0',
+    'stsynphot'
 ]
 
 setup_requirements = ['pytest-runner', ]