diff --git a/android-app/app/src/main/java/de/harheimertc/data/ApiService.kt b/android-app/app/src/main/java/de/harheimertc/data/ApiService.kt
index e5f82a3..690fd28 100755
--- a/android-app/app/src/main/java/de/harheimertc/data/ApiService.kt
+++ b/android-app/app/src/main/java/de/harheimertc/data/ApiService.kt
@@ -283,6 +283,7 @@ data class PushTokenRequest(
     val token: String,
     val platform: String = "android",
     val appVersion: String? = null,
+    val installationId: String? = null,
 )
 data class BirthdayDto(
     val name: String = "",
diff --git a/android-app/app/src/main/java/de/harheimertc/notifications/HarheimerMessagingService.kt b/android-app/app/src/main/java/de/harheimertc/notifications/HarheimerMessagingService.kt
index a4efcde..effa997 100755
--- a/android-app/app/src/main/java/de/harheimertc/notifications/HarheimerMessagingService.kt
+++ b/android-app/app/src/main/java/de/harheimertc/notifications/HarheimerMessagingService.kt
@@ -21,7 +21,7 @@ class HarheimerMessagingService : FirebaseMessagingService() {
     override fun onNewToken(token: String) {
         super.onNewToken(token)
         serviceScope.launch {
-            pushTokenRepository.registerToken(token)
+            pushTokenRepository.registerCurrentDevice()
         }
     }
 
diff --git a/android-app/app/src/main/java/de/harheimertc/repositories/PushTokenRepository.kt b/android-app/app/src/main/java/de/harheimertc/repositories/PushTokenRepository.kt
index 4cecdf3..f743f2a 100755
--- a/android-app/app/src/main/java/de/harheimertc/repositories/PushTokenRepository.kt
+++ b/android-app/app/src/main/java/de/harheimertc/repositories/PushTokenRepository.kt
@@ -1,6 +1,7 @@
 package de.harheimertc.repositories
 
 import android.util.Log
+import com.google.firebase.installations.FirebaseInstallations
 import com.google.firebase.messaging.FirebaseMessaging
 import de.harheimertc.BuildConfig
 import de.harheimertc.data.ApiService
@@ -15,16 +16,18 @@ class PushTokenRepository @Inject constructor(
 ) {
     suspend fun registerCurrentDevice(): Result<Unit> = runCatching {
         val token = FirebaseMessaging.getInstance().token.await()
-        registerToken(token).getOrThrow()
+        val installationId = FirebaseInstallations.getInstance().id.await()
+        registerToken(token, installationId).getOrThrow()
     }
 
-    suspend fun registerToken(token: String): Result<Unit> = runCatching {
+    suspend fun registerToken(token: String, installationId: String? = null): Result<Unit> = runCatching {
         if (token.isBlank()) return@runCatching
         retryOnNetworkFailure {
             val response = api.registerPushToken(
                 PushTokenRequest(
                     token = token,
                     appVersion = "${BuildConfig.VERSION_NAME}+${BuildConfig.VERSION_CODE}",
+                    installationId = installationId,
                 ),
             )
             if (!response.isSuccessful) {
diff --git a/server/api/profile/push-token.post.js b/server/api/profile/push-token.post.js
index fe8c57d..53613dc 100755
--- a/server/api/profile/push-token.post.js
+++ b/server/api/profile/push-token.post.js
@@ -22,7 +22,8 @@ export default defineEventHandler(async (event) => {
   upsertPushToken(users[userIndex], {
     token: body.token,
     platform: body.platform || 'android',
-    appVersion: body.appVersion || null
+    appVersion: body.appVersion || null,
+    installationId: body.installationId || null
   })
   await writeUsers(users)
   return { success: true, message: 'Push-Token gespeichert.' }
diff --git a/server/utils/push-notifications.js b/server/utils/push-notifications.js
index f2d946e..56137c7 100755
--- a/server/utils/push-notifications.js
+++ b/server/utils/push-notifications.js
@@ -85,16 +85,21 @@ function pushTokensForUser(user) {
     : []
 }
 
-export function upsertPushToken(user, { token, platform = 'android', appVersion = null }) {
+export function upsertPushToken(user, { token, platform = 'android', appVersion = null, installationId = null }) {
   const normalizedToken = String(token || '').trim()
   if (!normalizedToken) return user
+  const normalizedInstallationId = String(installationId || '').trim().slice(0, 200) || null
   const now = new Date().toISOString()
   const tokens = Array.isArray(user.pushTokens) ? user.pushTokens : []
-  const next = tokens.filter(entry => entry?.token !== normalizedToken)
+  // A Firebase token can rotate for the same app installation. Retain tokens
+  // from other devices, but replace the previous token of this installation.
+  const next = tokens.filter(entry => entry?.token !== normalizedToken &&
+    (!normalizedInstallationId || entry?.installationId !== normalizedInstallationId))
   next.push({
     token: normalizedToken,
     platform: String(platform || 'android').slice(0, 30),
     appVersion: appVersion ? String(appVersion).slice(0, 80) : null,
+    installationId: normalizedInstallationId,
     updatedAt: now,
     createdAt: tokens.find(entry => entry?.token === normalizedToken)?.createdAt || now
   })
diff --git a/tests/config-profile-endpoints.spec.ts b/tests/config-profile-endpoints.spec.ts
index 3d3e9bb..d0d2446 100755
--- a/tests/config-profile-endpoints.spec.ts
+++ b/tests/config-profile-endpoints.spec.ts
@@ -247,7 +247,7 @@ describe('Config & Profil Endpoints', () => {
 
     it('speichert Android-Push-Token am Benutzer', async () => {
       const event = createEvent({ headers: { authorization: 'Bearer android-token' } })
-      mockSuccessReadBody({ token: 'fcm-token', platform: 'android', appVersion: '1.0+1' })
+      mockSuccessReadBody({ token: 'fcm-token', platform: 'android', appVersion: '1.0+1', installationId: 'firebase-installation-id' })
       const users = [{ id: '1', email: 'max@test.de', roles: ['mitglied'] }]
       authUtils.verifyToken.mockReturnValue({ id: '1' })
       authUtils.getUserFromToken.mockResolvedValue(users[0])
@@ -260,7 +260,7 @@ describe('Config & Profil Endpoints', () => {
       expect(authUtils.writeUsers).toHaveBeenCalledWith([
         expect.objectContaining({
           id: '1',
-          pushTokens: [expect.objectContaining({ token: 'fcm-token', platform: 'android', appVersion: '1.0+1' })]
+          pushTokens: [expect.objectContaining({ token: 'fcm-token', platform: 'android', appVersion: '1.0+1', installationId: 'firebase-installation-id' })]
         })
       ])
     })