diff --git a/pyproject.toml b/pyproject.toml
index 97f013b..3d66155 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,6 +31,7 @@ dependencies = [
   "numpy>=1.20",
   "matplotlib",
   "scipy",
+  "astropy",
   "emcee",
   "dynesty"
   ]