diff --git a/pyproject.toml b/pyproject.toml
index 0996a6d..140aab4 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -37,7 +37,8 @@ dependencies = [
     "scipy >= 1.10.0",
     "scikit-image >= 0.20.0",
     "tqdm >= 4.65.0",
-    "gsd >= 3.2.0"
+    "gsd >= 3.2.0",
+    "chemfiles >= 0.10.4"
 ]
 
 [project.urls]