diff --git a/meta/Constraint.m b/meta/Constraint.m
index 1270f44e3..87d72d746 100644
--- a/meta/Constraint.m
+++ b/meta/Constraint.m
@@ -41,7 +41,9 @@
           Parameters`IsPhase[parameter],
           Parameters`SetPhase[parameter, value, modelName],
           True,
-          Print["Error: ", parameter, " is neither a model nor an input parameter!"];
+          Print["Error: ", parameter, " cannot be set in the constraint,",
+                " because it is neither a model nor an input parameter!"];
+          Quit[1];
           ""
          ];