diff --git a/ereuse_devicehub/resources/proof/models.py b/ereuse_devicehub/resources/proof/models.py
index 13b81cc9..4aa4f2fa 100644
--- a/ereuse_devicehub/resources/proof/models.py
+++ b/ereuse_devicehub/resources/proof/models.py
@@ -112,7 +112,7 @@ class ProofDataWipe(JoinedTableMixin, Proof):
 
 class ProofFunction(JoinedTableMixin, Proof):
     disk_usage = Column(db.Integer, default=0)
-    rate_id = Column(UUID, ForeignKey(Rate.id), nullable=False)
+    rate_id = Column(UUID(as_uuid=True), ForeignKey(Rate.id), nullable=False)
     rate = relationship(Rate,
                        backref=backref('proof_function',
                                        lazy=True,
diff --git a/ereuse_devicehub/resources/proof/schemas.py b/ereuse_devicehub/resources/proof/schemas.py
index 16a833b7..26479e50 100644
--- a/ereuse_devicehub/resources/proof/schemas.py
+++ b/ereuse_devicehub/resources/proof/schemas.py
@@ -45,8 +45,9 @@ class ProofDataWipe(Proof):
 
 class ProofFunction(Proof):
     __doc__ = m.ProofFunction.__doc__
-    disk_usage = Integer()
-    rate = NestedOn(s_action.Rate, required=True, only_query='id')
+    disk_usage = Integer(data_key='diskUsage')
+    rate = NestedOn(s_action.Rate, required=True,
+                    only_query='id', data_key='rateID')
 
 
 class ProofReuse(Proof):