diff --git a/src/somd2/config/_config.py b/src/somd2/config/_config.py
index 538ae57..db55ff4 100644
--- a/src/somd2/config/_config.py
+++ b/src/somd2/config/_config.py
@@ -703,7 +703,7 @@ def perturbable_constraint(self, perturbable_constraint):
             perturbable_constraint = perturbable_constraint.lower().replace(" ", "")
             if perturbable_constraint not in self._choices["perturbable_constraint"]:
                 raise ValueError(
-                    f"'perturbable_constrant' not recognised. Valid constraints are: {', '.join(self._choices['constraint'])}"
+                    f"'perturbable_constraint' not recognised. Valid constraints are: {', '.join(self._choices['perturbable_constraint'])}"
                 )
             else:
                 self._perturbable_constraint = perturbable_constraint