diff --git a/coordination-layer/constraints/vacuous.py b/coordination-layer/constraints/vacuous.py
index b41b471..76a3358 100644
--- a/coordination-layer/constraints/vacuous.py
+++ b/coordination-layer/constraints/vacuous.py
@@ -1,6 +1,7 @@
 from noir_constraint import NoirProof
 
 from constraints import Constraint
+from crypto import Field
 
 
 class Vacuous(Constraint):
@@ -8,6 +9,10 @@ class Vacuous(Constraint):
     This is the empty constraint, it return true for any proof
     """
 
+    def hash(self):
+        # chosen by a fair 2**64 sided die.
+        return Field(14500592324922987342)
+
     def prove(self) -> NoirProof:
         return NoirProof("vacuous")