diff --git a/firestore.rules b/firestore.rules
index d7149344..9d10dc61 100644
--- a/firestore.rules
+++ b/firestore.rules
@@ -10,6 +10,7 @@ service cloud.firestore {
 
     match /contracts/{contractId} {
       allow read;
+      allow update: if resource.data.creatorId == request.auth.uid && request.resource.data.keys().hasOnly(["description"]);
       allow delete: if resource.data.creatorId == request.auth.uid;
     }
 
diff --git a/web/components/contract-feed.tsx b/web/components/contract-feed.tsx
index 3e028e76..b5cfca3d 100644
--- a/web/components/contract-feed.tsx
+++ b/web/components/contract-feed.tsx
@@ -16,7 +16,7 @@ import { Comment, mapCommentsByBetId } from '../lib/firebase/comments'
 import dayjs from 'dayjs'
 import relativeTime from 'dayjs/plugin/relativeTime'
 import { OutcomeLabel } from './outcome-label'
-import { Contract, setContract } from '../lib/firebase/contracts'
+import { Contract, updateContract } from '../lib/firebase/contracts'
 import { useUser } from '../hooks/use-user'
 import { Linkify } from './linkify'
 import { Row } from './layout/row'
@@ -136,8 +136,10 @@ export function ContractDescription(props: {
   async function saveDescription(e: any) {
     e.preventDefault()
     setEditing(false)
-    contract.description = `${contract.description}\n${description}`.trim()
-    await setContract(contract)
+
+    const newDescription = `${contract.description}\n${description}`.trim()
+    await updateContract(contract.id, { description: newDescription })
+
     setDescription(editStatement())
   }
 
diff --git a/web/lib/firebase/contracts.ts b/web/lib/firebase/contracts.ts
index 891831c4..4300a2db 100644
--- a/web/lib/firebase/contracts.ts
+++ b/web/lib/firebase/contracts.ts
@@ -11,6 +11,7 @@ import {
   onSnapshot,
   orderBy,
   getDoc,
+  updateDoc,
 } from 'firebase/firestore'
 import dayjs from 'dayjs'
 import { Bet, getRecentBets } from './bets'
@@ -71,6 +72,14 @@ export async function setContract(contract: Contract) {
   await setDoc(docRef, contract)
 }
 
+export async function updateContract(
+  contractId: string,
+  update: Partial<Contract>
+) {
+  const docRef = doc(db, 'contracts', contractId)
+  await updateDoc(docRef, update)
+}
+
 export async function pushNewContract(contract: Omit<Contract, 'id'>) {
   const newContractRef = doc(contractCollection)
   const fullContract: Contract = { ...contract, id: newContractRef.id }