diff --git a/app/src/main/java/de/dreier/mytargets/features/settings/backup/BackupSettingsFragment.kt b/app/src/main/java/de/dreier/mytargets/features/settings/backup/BackupSettingsFragment.kt
index 812986826..9fbc6e60f 100644
--- a/app/src/main/java/de/dreier/mytargets/features/settings/backup/BackupSettingsFragment.kt
+++ b/app/src/main/java/de/dreier/mytargets/features/settings/backup/BackupSettingsFragment.kt
@@ -83,7 +83,7 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
      * bar. If a sync is active or pending, the progress is shown.
      */
     private val syncStatusObserver = SyncStatusObserver {
-        activity!!.runOnUiThread {
+        activity?.runOnUiThread {
             val account = GenericAccountService.account
             val syncActive = ContentResolver.isSyncActive(account, SyncUtils.CONTENT_AUTHORITY)
             val syncPending = ContentResolver.isSyncPending(account, SyncUtils.CONTENT_AUTHORITY)
@@ -93,7 +93,7 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
             binding.backupProgressBar.isIndeterminate = true
             binding.backupProgressBar.visibility = if (isRefreshing) VISIBLE else GONE
             if (wasRefreshing && !isRefreshing && backup != null) {
-                backup!!.getBackups(this)
+                backup?.getBackups(this)
             }
         }
     }
@@ -183,8 +183,7 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
     }
 
     override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
-        Timber.d("onActivityResult: ")
-        backup!!.onActivityResult(requestCode, resultCode, data)
+        backup?.onActivityResult(requestCode, resultCode, data)
         if (requestCode == IMPORT_FROM_URI && resultCode == AppCompatActivity.RESULT_OK && data != null) {
             importFromUri(data.data)
         }
@@ -203,7 +202,7 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
     }
 
     private fun onBackupIntervalClicked() {
-        val backupIntervals = Arrays.asList(*EBackupInterval.values())
+        val backupIntervals = listOf(*EBackupInterval.values())
         MaterialDialog.Builder(context!!)
             .title(R.string.backup_interval)
             .items(backupIntervals)
@@ -269,7 +268,7 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
             }
         })
         binding.recentBackupsList.adapter = adapter
-        backup!!.connect(
+        backup?.connect(
             context!!,
             object : IAsyncBackupRestore.ConnectionListener {
                 override fun onLoginCancelled() {
@@ -282,7 +281,7 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
 
                 override fun onConnected() {
                     updateBackupLocation()
-                    backup!!.getBackups(this@BackupSettingsFragment)
+                    backup?.getBackups(this@BackupSettingsFragment)
                 }
 
                 override fun onConnectionSuspended() {
@@ -301,7 +300,7 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
     private fun onBackupsLoaded(list: List<BackupEntry>) {
         binding.recentBackupsProgress.visibility = GONE
         binding.recentBackupsList.visibility = VISIBLE
-        adapter!!.setList(list.toMutableList())
+        adapter?.setList(list.toMutableList())
         binding.lastBackupLabel.visibility = if (list.isNotEmpty()) VISIBLE else GONE
         updateLabelTimer?.cancel()
         if (list.isNotEmpty()) {
@@ -359,7 +358,7 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
 
     private fun restoreBackup(item: BackupEntry) {
         val progress = showRestoreProgressDialog()
-        backup!!.restoreBackup(item,
+        backup?.restoreBackup(item,
             object : IAsyncBackupRestore.BackupStatusListener {
                 override fun onFinished() {
                     progress.dismiss()
@@ -374,10 +373,10 @@ class BackupSettingsFragment : SettingsFragmentBase(), IAsyncBackupRestore.OnLoa
     }
 
     private fun deleteBackup(backupEntry: BackupEntry) {
-        backup!!.deleteBackup(backupEntry, object : IAsyncBackupRestore.BackupStatusListener {
+        backup?.deleteBackup(backupEntry, object : IAsyncBackupRestore.BackupStatusListener {
             override fun onFinished() {
                 adapter!!.remove(backupEntry)
-                backup!!.getBackups(this@BackupSettingsFragment)
+                backup?.getBackups(this@BackupSettingsFragment)
             }
 
             override fun onError(message: String) {
diff --git a/app/src/main/java/de/dreier/mytargets/features/training/environment/CurrentWeather.kt b/app/src/main/java/de/dreier/mytargets/features/training/environment/CurrentWeather.kt
index 3e1ee57e6..f11df0306 100644
--- a/app/src/main/java/de/dreier/mytargets/features/training/environment/CurrentWeather.kt
+++ b/app/src/main/java/de/dreier/mytargets/features/training/environment/CurrentWeather.kt
@@ -20,15 +20,20 @@ import de.dreier.mytargets.features.settings.SettingsManager
 import de.dreier.mytargets.shared.models.EWeather
 import de.dreier.mytargets.shared.models.Environment
 import java.util.*
+import kotlin.math.pow
+import kotlin.math.roundToInt
 
 class CurrentWeather {
 
     @SerializedName("cod")
     var httpCode: Int? = null
+
     @SerializedName("name")
     var cityName: String = ""
+
     @SerializedName("weather")
     var weather: List<Weather> = ArrayList()
+
     @SerializedName("wind")
     var wind: Wind? = null
 
@@ -37,18 +42,18 @@ class CurrentWeather {
     }
 
     private fun kmhToBeaufort(kmh: Double): Int {
-        return Math.round(Math.pow(kmh / 3.01, 0.666666666)).toInt()
+        return (kmh / 3.01).pow(0.666666666).roundToInt()
     }
 
     fun toEnvironment(): Environment {
-        val code = Integer.parseInt(weather[0].icon!!.substring(0, 2))
+        val code = Integer.parseInt(weather[0].icon?.substring(0, 2) ?: "1")
         val e = Environment()
         e.indoor = SettingsManager.indoor
         e.weather = imageCodeToWeather(code)
         e.windDirection = 0
         e.location = cityName
         e.windDirection = 0
-        e.windSpeed = kmhToBeaufort(mpsToKmh(wind!!.speed!!))
+        e.windSpeed = kmhToBeaufort(mpsToKmh(wind?.speed ?: 0.0))
         return e
     }
 
diff --git a/build.gradle b/build.gradle
index 88f2d4873..015063a99 100644
--- a/build.gradle
+++ b/build.gradle
@@ -23,7 +23,7 @@ buildscript {
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.0-rc01'
+        classpath 'com.android.tools.build:gradle:3.5.0-rc02'
         classpath 'com.getkeepsafe.dexcount:dexcount-gradle-plugin:0.8.6'
         classpath 'com.google.gms:google-services:4.3.0'
         classpath 'com.google.firebase:firebase-plugins:2.0.0'