diff --git a/matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/CryptoStoreHelper.kt b/matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/CryptoStoreHelper.kt
index cea612dd..c0fc6c44 100644
--- a/matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/CryptoStoreHelper.kt
+++ b/matrix-sdk-android/src/androidTest/java/im/vector/matrix/android/internal/crypto/CryptoStoreHelper.kt
@@ -21,7 +21,7 @@ import im.vector.matrix.android.internal.crypto.store.IMXCryptoStore
 import im.vector.matrix.android.internal.crypto.store.db.RealmCryptoStore
 import im.vector.matrix.android.internal.crypto.store.db.RealmCryptoStoreModule
 import io.realm.RealmConfiguration
-import java.util.*
+import kotlin.random.Random
 
 internal class CryptoStoreHelper {
 
@@ -35,7 +35,7 @@ internal class CryptoStoreHelper {
     }
 
     fun createCredential() = Credentials(
-            userId = "userId_" + Random().nextInt(),
+            userId = "userId_" + Random.nextInt(),
             homeServer = "http://matrix.org",
             accessToken = "access_token",
             refreshToken = null,
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/comparators/DatedObjectComparators.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/comparators/DatedObjectComparators.kt
index aad33ab7..c9245e73 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/comparators/DatedObjectComparators.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/comparators/DatedObjectComparators.kt
@@ -17,7 +17,6 @@
 package im.vector.matrix.android.api.comparators
 
 import im.vector.matrix.android.api.interfaces.DatedObject
-import java.util.*
 
 object DatedObjectComparators {
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/extensions/MatrixSdkExtensions.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/extensions/MatrixSdkExtensions.kt
index e2e53904..180d80c5 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/extensions/MatrixSdkExtensions.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/extensions/MatrixSdkExtensions.kt
@@ -19,7 +19,7 @@ package im.vector.matrix.android.api.extensions
 import im.vector.matrix.android.api.comparators.DatedObjectComparators
 import im.vector.matrix.android.internal.crypto.model.MXDeviceInfo
 import im.vector.matrix.android.internal.crypto.model.rest.DeviceInfo
-import java.util.*
+import java.util.Collections
 
 /* ==========================================================================================
  * MXDeviceInfo
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/pushrules/RoomMemberCountCondition.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/pushrules/RoomMemberCountCondition.kt
index b2bed4c2..1c02d63d 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/pushrules/RoomMemberCountCondition.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/pushrules/RoomMemberCountCondition.kt
@@ -18,9 +18,8 @@ package im.vector.matrix.android.api.pushrules
 import im.vector.matrix.android.api.session.events.model.Event
 import im.vector.matrix.android.api.session.room.RoomService
 import timber.log.Timber
-import java.util.regex.Pattern
 
-private val regex = Pattern.compile("^(==|<=|>=|<|>)?(\\d*)$")
+private val regex = Regex("^(==|<=|>=|<|>)?(\\d*)$")
 
 class RoomMemberCountCondition(val `is`: String) : Condition(Kind.room_member_count) {
 
@@ -56,12 +55,9 @@ class RoomMemberCountCondition(val `is`: String) : Condition(Kind.room_member_co
      */
     private fun parseIsField(): Pair<String?, Int>? {
         try {
-            val match = regex.matcher(`is`)
-            if (match.find()) {
-                val prefix = match.group(1)
-                val count = match.group(2).toInt()
-                return prefix to count
-            }
+            val match = regex.find(`is`) ?: return null
+            val (prefix, count) = match.destructured
+            return prefix to count.toInt()
         } catch (t: Throwable) {
             Timber.d(t)
         }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/pushers/PushersService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/pushers/PushersService.kt
index 1450dbb5..c9054904 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/pushers/PushersService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/pushers/PushersService.kt
@@ -17,7 +17,7 @@ package im.vector.matrix.android.api.session.pushers
 
 import androidx.lifecycle.LiveData
 import im.vector.matrix.android.api.MatrixCallback
-import java.util.*
+import java.util.UUID
 
 
 interface PushersService {
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/create/CreateRoomParams.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/create/CreateRoomParams.kt
index 94d6e0a8..cdc1c952 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/create/CreateRoomParams.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/create/CreateRoomParams.kt
@@ -29,7 +29,6 @@ import im.vector.matrix.android.api.session.room.model.PowerLevels
 import im.vector.matrix.android.api.session.room.model.RoomDirectoryVisibility
 import im.vector.matrix.android.api.session.room.model.RoomHistoryVisibility
 import im.vector.matrix.android.internal.auth.data.ThreePidMedium
-import java.util.*
 
 /**
  * Parameter to create a room, with facilities functions to configure it
@@ -133,7 +132,7 @@ class CreateRoomParams {
             )
 
             if (null == initialStates) {
-                initialStates = Arrays.asList<Event>(algoEvent)
+                initialStates = mutableListOf(algoEvent)
             } else {
                 initialStates!!.add(algoEvent)
             }
@@ -166,7 +165,7 @@ class CreateRoomParams {
                                                content = contentMap.toContent())
 
             if (null == initialStates) {
-                initialStates = Arrays.asList<Event>(historyVisibilityEvent)
+                initialStates = mutableListOf(historyVisibilityEvent)
             } else {
                 initialStates!!.add(historyVisibilityEvent)
             }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/util/SecretStoringUtils.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/util/SecretStoringUtils.kt
index 6dc0d789..7b66f758 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/util/SecretStoringUtils.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/api/util/SecretStoringUtils.kt
@@ -27,7 +27,7 @@ import java.math.BigInteger
 import java.security.KeyPairGenerator
 import java.security.KeyStore
 import java.security.SecureRandom
-import java.util.*
+import java.util.Calendar
 import javax.crypto.*
 import javax.crypto.spec.GCMParameterSpec
 import javax.crypto.spec.IvParameterSpec
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/ObjectSigner.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/ObjectSigner.kt
index 29e20290..38d3e695 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/ObjectSigner.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/ObjectSigner.kt
@@ -17,7 +17,6 @@
 package im.vector.matrix.android.internal.crypto
 
 import im.vector.matrix.android.api.auth.data.Credentials
-import java.util.*
 import javax.inject.Inject
 
 internal class ObjectSigner @Inject constructor(private val credentials: Credentials,
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/olm/MXOlmDecryption.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/olm/MXOlmDecryption.kt
index b57486c1..60f319ac 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/olm/MXOlmDecryption.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/algorithms/olm/MXOlmDecryption.kt
@@ -31,7 +31,6 @@ import im.vector.matrix.android.internal.crypto.model.event.OlmPayloadContent
 import im.vector.matrix.android.internal.di.MoshiProvider
 import im.vector.matrix.android.internal.util.convertFromUTF8
 import timber.log.Timber
-import java.util.*
 
 internal class MXOlmDecryption(
         // The olm device interface
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/attachments/MXEncryptedAttachments.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/attachments/MXEncryptedAttachments.kt
index d8c62709..86ef488e 100755
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/attachments/MXEncryptedAttachments.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/attachments/MXEncryptedAttachments.kt
@@ -26,7 +26,6 @@ import java.io.ByteArrayOutputStream
 import java.io.InputStream
 import java.security.MessageDigest
 import java.security.SecureRandom
-import java.util.*
 import javax.crypto.Cipher
 import javax.crypto.spec.IvParameterSpec
 import javax.crypto.spec.SecretKeySpec
@@ -59,8 +58,7 @@ object MXEncryptedAttachments {
         // Half of the IV is random, the lower order bits are zeroed
         // such that the counter never wraps.
         // See https://github.com/matrix-org/matrix-ios-kit/blob/3dc0d8e46b4deb6669ed44f72ad79be56471354c/MatrixKit/Models/Room/MXEncryptedAttachments.m#L75
-        val initVectorBytes = ByteArray(16)
-        Arrays.fill(initVectorBytes, 0.toByte())
+        val initVectorBytes = ByteArray(16) { 0.toByte() }
 
         val ivRandomPart = ByteArray(8)
         secureRandom.nextBytes(ivRandomPart)
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackup.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackup.kt
index a69a7325..edd2e190 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackup.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackup.kt
@@ -66,9 +66,9 @@ import org.matrix.olm.OlmPkEncryption
 import org.matrix.olm.OlmPkMessage
 import timber.log.Timber
 import java.security.InvalidParameterException
-import java.util.*
 import javax.inject.Inject
 import kotlin.collections.HashMap
+import kotlin.random.Random
 
 /**
  * A KeysBackup class instance manage incremental backup of e2e keys (megolm keys)
@@ -114,8 +114,6 @@ internal class KeysBackup @Inject constructor(
     // The backup key being used.
     private var backupOlmPkEncryption: OlmPkEncryption? = null
 
-    private val random = Random()
-
     private var backupAllGroupSessionsCallback: MatrixCallback<Unit>? = null
 
     private var keysBackupStateListener: KeysBackupStateListener? = null
@@ -848,7 +846,7 @@ internal class KeysBackup @Inject constructor(
                 // Wait between 0 and 10 seconds, to avoid backup requests from
                 // different clients hitting the server all at the same time when a
                 // new key is sent
-                val delayInMs = random.nextInt(KEY_BACKUP_WAITING_TIME_TO_SEND_KEY_BACKUP_MILLIS).toLong()
+                val delayInMs = Random.nextInt(KEY_BACKUP_WAITING_TIME_TO_SEND_KEY_BACKUP_MILLIS).toLong()
 
                 uiHandler.postDelayed({ backupKeys() }, delayInMs)
             }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackupPassword.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackupPassword.kt
index e1ada61b..eabd5dff 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackupPassword.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackupPassword.kt
@@ -22,7 +22,7 @@ package im.vector.matrix.android.internal.crypto.keysbackup
 import androidx.annotation.WorkerThread
 import im.vector.matrix.android.api.listeners.ProgressListener
 import timber.log.Timber
-import java.util.*
+import java.util.UUID
 import javax.crypto.Mac
 import javax.crypto.spec.SecretKeySpec
 import kotlin.experimental.xor
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackupStateManager.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackupStateManager.kt
index ff812e75..cd74d04a 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackupStateManager.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/keysbackup/KeysBackupStateManager.kt
@@ -20,7 +20,6 @@ import android.os.Handler
 import im.vector.matrix.android.api.session.crypto.keysbackup.KeysBackupState
 import im.vector.matrix.android.api.session.crypto.keysbackup.KeysBackupStateListener
 import timber.log.Timber
-import java.util.*
 
 internal class KeysBackupStateManager(private val uiHandler: Handler) {
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXDeviceInfo.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXDeviceInfo.kt
index a458cdfe..36d6785e 100755
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXDeviceInfo.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXDeviceInfo.kt
@@ -23,7 +23,6 @@ import com.squareup.moshi.JsonClass
 import im.vector.matrix.android.api.util.JsonDict
 import im.vector.matrix.android.internal.crypto.model.rest.DeviceKeys
 import java.io.Serializable
-import java.util.*
 
 @JsonClass(generateAdapter = true)
 data class MXDeviceInfo(
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXKey.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXKey.kt
index 69019fbb..5655e653 100755
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXKey.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXKey.kt
@@ -18,7 +18,6 @@ package im.vector.matrix.android.internal.crypto.model
 
 import im.vector.matrix.android.api.util.JsonDict
 import timber.log.Timber
-import java.util.*
 
 data class MXKey(
         /**
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXUsersDevicesMap.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXUsersDevicesMap.kt
index a4b6e247..d3c76a14 100755
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXUsersDevicesMap.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/model/MXUsersDevicesMap.kt
@@ -16,7 +16,6 @@
 
 package im.vector.matrix.android.internal.crypto.model
 
-import java.util.*
 
 class MXUsersDevicesMap<E> {
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/SendToDeviceTask.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/SendToDeviceTask.kt
index 1865c633..7f3f4878 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/SendToDeviceTask.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/tasks/SendToDeviceTask.kt
@@ -21,8 +21,8 @@ import im.vector.matrix.android.internal.crypto.model.MXUsersDevicesMap
 import im.vector.matrix.android.internal.crypto.model.rest.SendToDeviceBody
 import im.vector.matrix.android.internal.network.executeRequest
 import im.vector.matrix.android.internal.task.Task
-import java.util.*
 import javax.inject.Inject
+import kotlin.random.Random
 
 internal interface SendToDeviceTask : Task<SendToDeviceTask.Params, Unit> {
     data class Params(
@@ -45,7 +45,7 @@ internal class DefaultSendToDeviceTask @Inject constructor(private val cryptoApi
         return executeRequest {
             apiCall = cryptoApi.sendToDevice(
                     params.eventType,
-                    params.transactionId ?: Random().nextInt(Integer.MAX_VALUE).toString(),
+                    params.transactionId ?: Random.nextInt(Integer.MAX_VALUE).toString(),
                     sendToDeviceBody
             )
         }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultSasVerificationService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultSasVerificationService.kt
index 6eea9ab5..35a23535 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultSasVerificationService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/verification/DefaultSasVerificationService.kt
@@ -44,7 +44,7 @@ import im.vector.matrix.android.internal.util.MatrixCoroutineDispatchers
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.launch
 import timber.log.Timber
-import java.util.*
+import java.util.UUID
 import javax.inject.Inject
 import kotlin.collections.HashMap
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/mapper/RoomSummaryMapper.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/mapper/RoomSummaryMapper.kt
index 95d4d8bc..3ec51226 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/mapper/RoomSummaryMapper.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/database/mapper/RoomSummaryMapper.kt
@@ -22,7 +22,7 @@ import im.vector.matrix.android.api.session.room.model.RoomSummary
 import im.vector.matrix.android.api.session.room.model.tag.RoomTag
 import im.vector.matrix.android.internal.crypto.algorithms.olm.OlmDecryptionResult
 import im.vector.matrix.android.internal.database.model.RoomSummaryEntity
-import java.util.*
+import java.util.UUID
 import javax.inject.Inject
 
 internal class RoomSummaryMapper @Inject constructor(
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/CertUtil.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/CertUtil.kt
index 64e941a6..976cbde1 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/CertUtil.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/CertUtil.kt
@@ -24,7 +24,6 @@ import java.security.KeyStore
 import java.security.MessageDigest
 import java.security.cert.CertificateException
 import java.security.cert.X509Certificate
-import java.util.*
 import javax.net.ssl.*
 import kotlin.experimental.and
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/TLSSocketFactory.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/TLSSocketFactory.kt
index e249ed74..761a18c8 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/TLSSocketFactory.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/network/ssl/TLSSocketFactory.kt
@@ -25,7 +25,6 @@ import java.net.UnknownHostException
 import java.security.KeyManagementException
 import java.security.NoSuchAlgorithmException
 import java.security.SecureRandom
-import java.util.*
 import javax.net.ssl.SSLContext
 import javax.net.ssl.SSLSocket
 import javax.net.ssl.SSLSocketFactory
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/content/DefaultContentUploadStateTracker.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/content/DefaultContentUploadStateTracker.kt
index 4bb58fe7..e44c8eb5 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/content/DefaultContentUploadStateTracker.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/content/DefaultContentUploadStateTracker.kt
@@ -30,9 +30,8 @@ internal class DefaultContentUploadStateTracker @Inject constructor() : ContentU
     private val listeners = mutableMapOf<String, MutableList<ContentUploadStateTracker.UpdateListener>>()
 
     override fun track(key: String, updateListener: ContentUploadStateTracker.UpdateListener) {
-        val listeners = listeners[key] ?: ArrayList()
+        val listeners = listeners.getOrPut(key) { ArrayList() }
         listeners.add(updateListener)
-        this.listeners[key] = listeners
         val currentState = states[key] ?: ContentUploadStateTracker.State.Idle
         mainHandler.post { updateListener.onUpdate(currentState) }
     }
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/pushers/DefaultPusherService.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/pushers/DefaultPusherService.kt
index 1c03a4f7..995d9331 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/pushers/DefaultPusherService.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/pushers/DefaultPusherService.kt
@@ -32,7 +32,7 @@ import im.vector.matrix.android.internal.task.configureWith
 import im.vector.matrix.android.internal.worker.WorkManagerUtil
 import im.vector.matrix.android.internal.worker.WorkManagerUtil.matrixOneTimeWorkRequestBuilder
 import im.vector.matrix.android.internal.worker.WorkerParamsFactory
-import java.util.*
+import java.util.UUID
 import java.util.concurrent.TimeUnit
 import javax.inject.Inject
 
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoEventFactory.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoEventFactory.kt
index 6d97da84..d757d69a 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoEventFactory.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/send/LocalEchoEventFactory.kt
@@ -38,7 +38,7 @@ import im.vector.matrix.android.internal.session.room.RoomSummaryUpdater
 import im.vector.matrix.android.internal.util.StringProvider
 import org.commonmark.parser.Parser
 import org.commonmark.renderer.html.HtmlRenderer
-import java.util.*
+import java.util.UUID
 import javax.inject.Inject
 
 /**
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/RoomTagHandler.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/RoomTagHandler.kt
index a3c00e43..e1b9d83d 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/RoomTagHandler.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/sync/RoomTagHandler.kt
@@ -21,7 +21,6 @@ import im.vector.matrix.android.internal.database.model.RoomSummaryEntity
 import im.vector.matrix.android.internal.database.model.RoomTagEntity
 import im.vector.matrix.android.internal.database.query.where
 import io.realm.Realm
-import java.util.*
 import javax.inject.Inject
 
 internal class RoomTagHandler @Inject constructor() {
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/CancelableWork.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/CancelableWork.kt
index ebd20ec6..ddaeb1fd 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/CancelableWork.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/CancelableWork.kt
@@ -19,7 +19,7 @@ package im.vector.matrix.android.internal.util
 import android.content.Context
 import androidx.work.WorkManager
 import im.vector.matrix.android.api.util.Cancelable
-import java.util.*
+import java.util.UUID
 
 internal class CancelableWork(private val context: Context,
                               private val workId: UUID) : Cancelable {
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/CompatUtil.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/CompatUtil.kt
index e713c435..d0a5f2f8 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/CompatUtil.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/CompatUtil.kt
@@ -34,7 +34,7 @@ import java.security.*
 import java.security.cert.CertificateException
 import java.security.spec.AlgorithmParameterSpec
 import java.security.spec.RSAKeyGenParameterSpec
-import java.util.*
+import java.util.Calendar
 import java.util.zip.GZIPOutputStream
 import javax.crypto.*
 import javax.crypto.spec.GCMParameterSpec
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/JsonCanonicalizer.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/JsonCanonicalizer.kt
index 36c1ba15..d8f059f4 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/JsonCanonicalizer.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/util/JsonCanonicalizer.kt
@@ -22,7 +22,7 @@ import org.json.JSONArray
 import org.json.JSONException
 import org.json.JSONObject
 import timber.log.Timber
-import java.util.*
+import java.util.TreeSet
 
 /**
  * Build canonical Json