diff --git a/.idea/codeStyles/Project.xml b/.idea/codeStyles/Project.xml
index 40ee4ee5cf..b3719669fd 100644
--- a/.idea/codeStyles/Project.xml
+++ b/.idea/codeStyles/Project.xml
@@ -1,9 +1,6 @@
 <component name="ProjectCodeStyleConfiguration">
   <code_scheme name="Project" version="173">
     <option name="RIGHT_MARGIN" value="160" />
-    <AndroidXmlCodeStyleSettings>
-      <option name="ARRANGEMENT_SETTINGS_MIGRATED_TO_191" value="true" />
-    </AndroidXmlCodeStyleSettings>
     <JetCodeStyleSettings>
       <option name="PACKAGES_TO_USE_STAR_IMPORTS">
         <value>
diff --git a/CHANGES.md b/CHANGES.md
index 9a440f9084..63dad2ade6 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -31,6 +31,7 @@ Other changes:
  - Fix minor typo in contribution guide (#1512)
  - Fix self-assignment of callback in `DefaultRoomPushRuleService#setRoomNotificationState` (#1520)
  - Random housekeeping clean-ups indicated by Lint (#1520, #1541)
+ - Keys Backup API now use the unstable prefix (#1503)
 
 Changes in RiotX 0.22.0 (2020-06-15)
 ===================================================
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/api/RoomKeysApi.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/api/RoomKeysApi.kt
index beaee58a3e..75de995be3 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/api/RoomKeysApi.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/api/RoomKeysApi.kt
@@ -47,14 +47,14 @@ internal interface RoomKeysApi {
      * Create a new keys backup version.
      * @param createKeysBackupVersionBody the body
      */
-    @POST(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/version")
+    @POST(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/version")
     fun createKeysBackupVersion(@Body createKeysBackupVersionBody: CreateKeysBackupVersionBody): Call<KeysVersion>
 
     /**
      * Get the key backup last version
      * If not supported by the server, an error is returned: {"errcode":"M_NOT_FOUND","error":"No backup found"}
      */
-    @GET(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/version")
+    @GET(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/version")
     fun getKeysBackupLastVersion(): Call<KeysVersionResult>
 
     /**
@@ -63,7 +63,7 @@ internal interface RoomKeysApi {
      *
      * @param version  version
      */
-    @GET(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/version/{version}")
+    @GET(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/version/{version}")
     fun getKeysBackupVersion(@Path("version") version: String): Call<KeysVersionResult>
 
     /**
@@ -71,7 +71,7 @@ internal interface RoomKeysApi {
      * @param version                     version
      * @param updateKeysBackupVersionBody the body
      */
-    @PUT(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/version/{version}")
+    @PUT(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/version/{version}")
     fun updateKeysBackupVersion(@Path("version") version: String,
                                 @Body keysBackupVersionBody: UpdateKeysBackupVersionBody): Call<Unit>
 
@@ -93,7 +93,7 @@ internal interface RoomKeysApi {
      * @param version       the version of the backup
      * @param keyBackupData the data to send
      */
-    @PUT(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys/{roomId}/{sessionId}")
+    @PUT(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys/{roomId}/{sessionId}")
     fun storeRoomSessionData(@Path("roomId") roomId: String,
                              @Path("sessionId") sessionId: String,
                              @Query("version") version: String,
@@ -106,7 +106,7 @@ internal interface RoomKeysApi {
      * @param version            the version of the backup
      * @param roomKeysBackupData the data to send
      */
-    @PUT(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys/{roomId}")
+    @PUT(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys/{roomId}")
     fun storeRoomSessionsData(@Path("roomId") roomId: String,
                               @Query("version") version: String,
                               @Body roomKeysBackupData: RoomKeysBackupData): Call<BackupKeysResult>
@@ -117,7 +117,7 @@ internal interface RoomKeysApi {
      * @param version        the version of the backup
      * @param keysBackupData the data to send
      */
-    @PUT(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys")
+    @PUT(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys")
     fun storeSessionsData(@Query("version") version: String,
                           @Body keysBackupData: KeysBackupData): Call<BackupKeysResult>
 
@@ -132,7 +132,7 @@ internal interface RoomKeysApi {
      * @param sessionId the session id
      * @param version   the version of the backup, or empty String to retrieve the last version
      */
-    @GET(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys/{roomId}/{sessionId}")
+    @GET(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys/{roomId}/{sessionId}")
     fun getRoomSessionData(@Path("roomId") roomId: String,
                            @Path("sessionId") sessionId: String,
                            @Query("version") version: String): Call<KeyBackupData>
@@ -143,7 +143,7 @@ internal interface RoomKeysApi {
      * @param roomId   the room id
      * @param version  the version of the backup, or empty String to retrieve the last version
      */
-    @GET(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys/{roomId}")
+    @GET(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys/{roomId}")
     fun getRoomSessionsData(@Path("roomId") roomId: String,
                             @Query("version") version: String): Call<RoomKeysBackupData>
 
@@ -152,7 +152,7 @@ internal interface RoomKeysApi {
      *
      * @param version  the version of the backup, or empty String to retrieve the last version
      */
-    @GET(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys")
+    @GET(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys")
     fun getSessionsData(@Query("version") version: String): Call<KeysBackupData>
 
     /* ==========================================================================================
@@ -162,7 +162,7 @@ internal interface RoomKeysApi {
     /**
      * Deletes keys from the backup.
      */
-    @DELETE(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys/{roomId}/{sessionId}")
+    @DELETE(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys/{roomId}/{sessionId}")
     fun deleteRoomSessionData(@Path("roomId") roomId: String,
                               @Path("sessionId") sessionId: String,
                               @Query("version") version: String): Call<Unit>
@@ -170,14 +170,14 @@ internal interface RoomKeysApi {
     /**
      * Deletes keys from the backup.
      */
-    @DELETE(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys/{roomId}")
+    @DELETE(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys/{roomId}")
     fun deleteRoomSessionsData(@Path("roomId") roomId: String,
                                @Query("version") version: String): Call<Unit>
 
     /**
      * Deletes keys from the backup.
      */
-    @DELETE(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/keys")
+    @DELETE(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/keys")
     fun deleteSessionsData(@Query("version") version: String): Call<Unit>
 
     /* ==========================================================================================
@@ -187,6 +187,6 @@ internal interface RoomKeysApi {
     /**
      * Deletes a backup.
      */
-    @DELETE(NetworkConstants.URI_API_PREFIX_PATH_R0 + "room_keys/version/{version}")
+    @DELETE(NetworkConstants.URI_API_PREFIX_PATH_UNSTABLE + "room_keys/version/{version}")
     fun deleteBackup(@Path("version") version: String): Call<Unit>
 }