diff --git a/pyproject.toml b/pyproject.toml
index 8571f3f..665e88c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -18,6 +18,7 @@ maintainers = [
 dependencies = [
     "agjax",
     "ceviche_challenges",
+    "fmmax",
     "jax",
     "jaxlib",
     "numpy",