diff --git a/app/entities.py b/app/entities.py
index 19c0deb..b8a447e 100644
--- a/app/entities.py
+++ b/app/entities.py
@@ -164,7 +164,7 @@ class Consumable(db.Model):
     name = db.Column(db.String(255), unique=True)
     unit = db.Column(db.String(255))
 
-    vehicles = db.relationship("Vehicle", secondary=vehicles_consumables)
+    vehicles = db.relationship("Vehicle", secondary=vehicles_consumables, viewonly=True)
 
     def __init__(self, name, unit):
         self.name = name