diff --git a/pyproject.toml b/pyproject.toml
index 1ebc3419b6..26ef11b4ec 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -72,7 +72,7 @@ openmm = [
 fireworks = ["fireworks==2.1.3"]
 strict-openff = [
     "mdanalysis==2.10.0",
-    "monty==2026.2.18",
+    "monty==2026.5.18",
     "openmm-mdanalysis-reporter==0.1.0",
     "openmm==8.5.1",
     "pymatgen==2026.5.4", # EXERCISE CAUTION WHEN UPDATING - open ff is extremely sensitive to pymatgen version