diff --git a/common/util/clean-username.ts b/common/util/clean-username.ts
index 5c295aeb..10da8376 100644
--- a/common/util/clean-username.ts
+++ b/common/util/clean-username.ts
@@ -7,6 +7,6 @@ export const cleanUsername = (name: string, maxLength = 25) => {
     .substring(0, maxLength)
 }
 
-export const cleanDisplayName = (displayName: string, maxLength = 25) => {
+export const cleanDisplayName = (displayName: string, maxLength = 30) => {
   return displayName.replace(/\s+/g, ' ').substring(0, maxLength).trim()
 }
diff --git a/functions/src/analytics.ts b/functions/src/analytics.ts
index 9c01fe36..d178ee0f 100644
--- a/functions/src/analytics.ts
+++ b/functions/src/analytics.ts
@@ -5,7 +5,7 @@ import { PROD_CONFIG } from '../../common/envs/prod'
 
 import { isProd } from './utils'
 
-const key = isProd ? PROD_CONFIG.amplitudeApiKey : DEV_CONFIG.amplitudeApiKey
+const key = isProd() ? PROD_CONFIG.amplitudeApiKey : DEV_CONFIG.amplitudeApiKey
 
 const amp = Amplitude.init(key ?? '')
 
diff --git a/functions/src/change-user-info.ts b/functions/src/change-user-info.ts
index ab15eb70..118d5c67 100644
--- a/functions/src/change-user-info.ts
+++ b/functions/src/change-user-info.ts
@@ -5,7 +5,10 @@ import { getUser } from './utils'
 import { Contract } from '../../common/contract'
 import { Comment } from '../../common/comment'
 import { User } from '../../common/user'
-import { cleanUsername } from '../../common/util/clean-username'
+import {
+  cleanUsername,
+  cleanDisplayName,
+} from '../../common/util/clean-username'
 import { removeUndefinedProps } from '../../common/util/object'
 import { Answer } from '../../common/answer'
 
@@ -63,6 +66,10 @@ export const changeUser = async (
       }
     }
 
+    if (update.name) {
+      update.name = cleanDisplayName(update.name)
+    }
+
     const userRef = firestore.collection('users').doc(user.id)
     const userUpdate: Partial<User> = removeUndefinedProps(update)
 
diff --git a/functions/src/resolve-market.ts b/functions/src/resolve-market.ts
index 894f1492..43cb4839 100644
--- a/functions/src/resolve-market.ts
+++ b/functions/src/resolve-market.ts
@@ -129,7 +129,7 @@ export const resolveMarket = functions
       const openBets = bets.filter((b) => !b.isSold && !b.sale)
       const loanPayouts = getLoanPayouts(openBets)
 
-      if (!isProd)
+      if (!isProd())
         console.log(
           'payouts:',
           payouts,
diff --git a/functions/src/scripts/clean-display-names.ts b/functions/src/scripts/clean-display-names.ts
new file mode 100644
index 00000000..8dd2a3d3
--- /dev/null
+++ b/functions/src/scripts/clean-display-names.ts
@@ -0,0 +1,26 @@
+// For a while, we didn't enforce that display names would be clean in the `updateUserInfo`
+// cloud function, so this script hunts down unclean ones.
+
+import * as admin from 'firebase-admin'
+import { initAdmin } from './script-init'
+import { cleanDisplayName } from '../../../common/util/clean-username'
+import { log, writeUpdatesAsync, UpdateSpec } from '../utils'
+initAdmin()
+const firestore = admin.firestore()
+
+if (require.main === module) {
+  const usersColl = firestore.collection('users')
+  usersColl.get().then(async (userSnaps) => {
+    log(`Loaded ${userSnaps.size} users.`)
+    const updates = userSnaps.docs.reduce((acc, u) => {
+      const name = u.data().name
+      if (name != cleanDisplayName(name)) {
+        acc.push({ doc: u.ref, fields: { name: cleanDisplayName(name) } })
+      }
+      return acc
+    }, [] as UpdateSpec[])
+    log(`Found ${updates.length} users to update:`, updates)
+    await writeUpdatesAsync(firestore, updates)
+    log(`Updated all users.`)
+  })
+}
diff --git a/functions/src/stripe.ts b/functions/src/stripe.ts
index 6fbc182c..67309aa8 100644
--- a/functions/src/stripe.ts
+++ b/functions/src/stripe.ts
@@ -28,7 +28,7 @@ const initStripe = () => {
 }
 
 // manage at https://dashboard.stripe.com/test/products?active=true
-const manticDollarStripePrice = isProd
+const manticDollarStripePrice = isProd()
   ? {
       500: 'price_1KFQXcGdoFKoCJW770gTNBrm',
       1000: 'price_1KFQp1GdoFKoCJW7Iu0dsF65',
diff --git a/functions/src/utils.ts b/functions/src/utils.ts
index 9cac3409..a95ac858 100644
--- a/functions/src/utils.ts
+++ b/functions/src/utils.ts
@@ -15,7 +15,7 @@ export const logMemory = () => {
   }
 }
 
-type UpdateSpec = {
+export type UpdateSpec = {
   doc: admin.firestore.DocumentReference
   fields: { [k: string]: unknown }
 }
@@ -36,8 +36,9 @@ export const writeUpdatesAsync = async (
   }
 }
 
-export const isProd =
-  admin.instanceId().app.options.projectId === 'mantic-markets'
+export const isProd = () => {
+  return admin.instanceId().app.options.projectId === 'mantic-markets'
+}
 
 export const getDoc = async <T>(collection: string, doc: string) => {
   const snap = await admin.firestore().collection(collection).doc(doc).get()
@@ -69,6 +70,7 @@ export const getPrivateUser = (userId: string) => {
 }
 
 export const getUserByUsername = async (username: string) => {
+  const firestore = admin.firestore()
   const snap = await firestore
     .collection('users')
     .where('username', '==', username)
@@ -77,13 +79,12 @@ export const getUserByUsername = async (username: string) => {
   return snap.empty ? undefined : (snap.docs[0].data() as User)
 }
 
-const firestore = admin.firestore()
-
 const updateUserBalance = (
   userId: string,
   delta: number,
   isDeposit = false
 ) => {
+  const firestore = admin.firestore()
   return firestore.runTransaction(async (transaction) => {
     const userDoc = firestore.doc(`users/${userId}`)
     const userSnap = await transaction.get(userDoc)