diff --git a/pyproject.toml b/pyproject.toml
index 66d34842fbff613b0a13ca7033bcd81db70497c0..718cadf328fbcf156023670562799979cfeae04c 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -12,7 +12,7 @@ authors = [
 ]
 license = { file = "COPYING.txt" }
 requires-python = ">=3.10"
-dependencies = ["sympy>=1.6,<=1.11.1", "numpy>=1.8.0", "appdirs", "joblib", "pyyaml"]
+dependencies = ["sympy>=1.6,<=1.11.1", "numpy>=1.8.0", "appdirs", "joblib", "pyyaml", "pymbolic>=2022.2"]
 classifiers = [
     "Development Status :: 4 - Beta",
     "Framework :: Jupyter",