diff --git a/app/src/main/java/eu/kanade/tachiyomi/source/online/all/MangaDex.kt b/app/src/main/java/eu/kanade/tachiyomi/source/online/all/MangaDex.kt
index 21a99702a..85fd82516 100644
--- a/app/src/main/java/eu/kanade/tachiyomi/source/online/all/MangaDex.kt
+++ b/app/src/main/java/eu/kanade/tachiyomi/source/online/all/MangaDex.kt
@@ -13,6 +13,7 @@ import eu.kanade.tachiyomi.data.track.TrackManager
 import eu.kanade.tachiyomi.network.GET
 import eu.kanade.tachiyomi.network.POST
 import eu.kanade.tachiyomi.network.asObservableSuccess
+import eu.kanade.tachiyomi.network.await
 import eu.kanade.tachiyomi.source.Source
 import eu.kanade.tachiyomi.source.model.FilterList
 import eu.kanade.tachiyomi.source.model.MangasPage
@@ -190,7 +191,7 @@ class MangaDex(delegate: HttpSource, val context: Context) :
                     headers,
                     formBody.build()
                 )
-            ).execute()
+            ).await()
 
             response.body!!.string().let {
                 if (it.isEmpty()) {
diff --git a/app/src/main/java/exh/debug/DebugToggles.kt b/app/src/main/java/exh/debug/DebugToggles.kt
index e43006aad..911475bfc 100644
--- a/app/src/main/java/exh/debug/DebugToggles.kt
+++ b/app/src/main/java/exh/debug/DebugToggles.kt
@@ -3,6 +3,7 @@ package exh.debug
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import uy.kohesive.injekt.injectLazy
+import java.util.Locale
 
 enum class DebugToggles(val default: Boolean) {
     // Redirect to master version of gallery when encountering a gallery that has a parent/child that is already in the library
@@ -16,7 +17,7 @@ enum class DebugToggles(val default: Boolean) {
     // Pretend that all galleries only have a single version
     INCLUDE_ONLY_ROOT_WHEN_LOADING_EXH_VERSIONS(false);
 
-    val prefKey = "eh_debug_toggle_${name.toLowerCase()}"
+    val prefKey = "eh_debug_toggle_${name.toLowerCase(Locale.getDefault())}"
 
     @OptIn(ExperimentalCoroutinesApi::class)
     var enabled: Boolean
diff --git a/app/src/main/java/exh/debug/SettingsDebugController.kt b/app/src/main/java/exh/debug/SettingsDebugController.kt
index 01ae2daa7..bf30745ba 100644
--- a/app/src/main/java/exh/debug/SettingsDebugController.kt
+++ b/app/src/main/java/exh/debug/SettingsDebugController.kt
@@ -15,6 +15,7 @@ import eu.kanade.tachiyomi.util.preference.onClick
 import eu.kanade.tachiyomi.util.preference.preference
 import eu.kanade.tachiyomi.util.preference.preferenceCategory
 import eu.kanade.tachiyomi.util.preference.switchPreference
+import java.util.Locale
 import kotlin.reflect.KVisibility
 import kotlin.reflect.full.declaredFunctions
 
@@ -30,7 +31,7 @@ class SettingsDebugController : SettingsController() {
                 it.visibility == KVisibility.PUBLIC
             }.forEach {
                 preference {
-                    title = it.name.replace(Regex("(.)(\\p{Upper})"), "$1 $2").toLowerCase().capitalize()
+                    title = it.name.replace(Regex("(.)(\\p{Upper})"), "$1 $2").toLowerCase(Locale.getDefault()).capitalize(Locale.getDefault())
                     isPersistent = false
 
                     onClick {
@@ -61,7 +62,7 @@ class SettingsDebugController : SettingsController() {
 
             DebugToggles.values().forEach {
                 switchPreference {
-                    title = it.name.replace('_', ' ').toLowerCase().capitalize()
+                    title = it.name.replace('_', ' ').toLowerCase(Locale.getDefault()).capitalize(Locale.getDefault())
                     key = it.prefKey
                     defaultValue = it.default
                     summaryOn = if (it.default) "" else MODIFIED_TEXT
diff --git a/app/src/main/java/exh/log/EHDebugModeOverlay.kt b/app/src/main/java/exh/log/EHDebugModeOverlay.kt
index 046f5e19e..d428fa442 100644
--- a/app/src/main/java/exh/log/EHDebugModeOverlay.kt
+++ b/app/src/main/java/exh/log/EHDebugModeOverlay.kt
@@ -13,6 +13,7 @@ import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import eu.kanade.tachiyomi.util.system.dpToPx
 import uy.kohesive.injekt.injectLazy
+import java.util.Locale
 
 class EHDebugModeOverlay(private val context: Context) : OverlayModule<String>(null, null) {
     private var textView: TextView? = null
@@ -57,7 +58,7 @@ class EHDebugModeOverlay(private val context: Context) : OverlayModule<String>(n
         <b>Debug mode:</b> ${BuildConfig.DEBUG.asEnabledString()}<br>
         <b>Version code:</b> ${BuildConfig.VERSION_CODE}<br>
         <b>Commit SHA:</b> ${BuildConfig.COMMIT_SHA}<br>
-        <b>Log level:</b> ${EHLogLevel.currentLogLevel.name.toLowerCase()}<br>
+        <b>Log level:</b> ${EHLogLevel.currentLogLevel.name.toLowerCase(Locale.getDefault())}<br>
         <b>Source blacklist:</b> ${prefs.eh_enableSourceBlacklist().get().asEnabledString()}
         """.trimIndent()
 
diff --git a/app/src/main/java/exh/search/SearchEngine.kt b/app/src/main/java/exh/search/SearchEngine.kt
index 1ddaa5f63..6b129711a 100755
--- a/app/src/main/java/exh/search/SearchEngine.kt
+++ b/app/src/main/java/exh/search/SearchEngine.kt
@@ -3,6 +3,7 @@ package exh.search
 import exh.metadata.sql.tables.SearchMetadataTable
 import exh.metadata.sql.tables.SearchTagTable
 import exh.metadata.sql.tables.SearchTitleTable
+import java.util.Locale
 
 class SearchEngine {
     private val queryCache = mutableMapOf<String, List<QueryComponent>>()
@@ -162,7 +163,7 @@ class SearchEngine {
             }
         }
 
-        query.toLowerCase().forEach { char ->
+        query.toLowerCase(Locale.getDefault()).forEach { char ->
             if (char == '"') {
                 inQuotes = !inQuotes
             } else if (enableWildcard && (char == '?' || char == '_')) {
diff --git a/app/src/main/java/exh/smartsearch/SmartSearchEngine.kt b/app/src/main/java/exh/smartsearch/SmartSearchEngine.kt
index 943199a32..537c38cf7 100644
--- a/app/src/main/java/exh/smartsearch/SmartSearchEngine.kt
+++ b/app/src/main/java/exh/smartsearch/SmartSearchEngine.kt
@@ -6,13 +6,13 @@ import eu.kanade.tachiyomi.source.CatalogueSource
 import eu.kanade.tachiyomi.source.model.FilterList
 import eu.kanade.tachiyomi.source.model.SManga
 import eu.kanade.tachiyomi.util.lang.await
+import eu.kanade.tachiyomi.util.lang.awaitSingle
 import info.debatty.java.stringsimilarity.NormalizedLevenshtein
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.async
 import kotlinx.coroutines.supervisorScope
-import rx.schedulers.Schedulers
 import uy.kohesive.injekt.injectLazy
+import java.util.Locale
 
 class SmartSearchEngine(
     private val extraSearchParams: String? = null
@@ -21,7 +21,6 @@ class SmartSearchEngine(
 
     private val normalizedLevenshtein = NormalizedLevenshtein()
 
-    @OptIn(ExperimentalCoroutinesApi::class)
     suspend fun smartSearch(source: CatalogueSource, title: String): SManga? {
         val cleanedTitle = cleanSmartSearchTitle(title)
 
@@ -34,8 +33,7 @@ class SmartSearchEngine(
                         "$query ${extraSearchParams.trim()}"
                     } else query
 
-                    val searchResults = source.fetchSearchManga(1, builtQuery, FilterList())
-                        .toSingle().await(Schedulers.io())
+                    val searchResults = source.fetchSearchManga(1, builtQuery, FilterList()).awaitSingle()
 
                     searchResults.mangas.map {
                         val cleanedMangaTitle = cleanSmartSearchTitle(it.originalTitle)
@@ -51,13 +49,12 @@ class SmartSearchEngine(
         return eligibleManga.maxByOrNull { it.dist }?.manga
     }
 
-    @OptIn(ExperimentalCoroutinesApi::class)
     suspend fun normalSearch(source: CatalogueSource, title: String): SManga? {
         val eligibleManga = supervisorScope {
             val searchQuery = if (extraSearchParams != null) {
                 "$title ${extraSearchParams.trim()}"
             } else title
-            val searchResults = source.fetchSearchManga(1, searchQuery, FilterList()).toSingle().await(Schedulers.io())
+            val searchResults = source.fetchSearchManga(1, searchQuery, FilterList()).awaitSingle()
 
             if (searchResults.mangas.size == 1) {
                 return@supervisorScope listOf(SearchEntry(searchResults.mangas.first(), 0.0))
@@ -102,7 +99,7 @@ class SmartSearchEngine(
     }
 
     private fun cleanSmartSearchTitle(title: String): String {
-        val preTitle = title.toLowerCase()
+        val preTitle = title.toLowerCase(Locale.getDefault())
 
         // Remove text in brackets
         var cleanedTitle = removeTextInBrackets(preTitle, true)
@@ -152,6 +149,7 @@ class SmartSearchEngine(
                 if (closingBracketDepthIndex != null) {
                     depthPairs[closingBracketDepthIndex]--
                 } else {
+                    @Suppress("ControlFlowWithEmptyBody")
                     if (depthPairs.all { it <= 0 }) {
                         result.append(c)
                     } else {
diff --git a/app/src/main/java/exh/uconfig/EHConfigurator.kt b/app/src/main/java/exh/uconfig/EHConfigurator.kt
index a1f08fcf0..943c3d7e5 100644
--- a/app/src/main/java/exh/uconfig/EHConfigurator.kt
+++ b/app/src/main/java/exh/uconfig/EHConfigurator.kt
@@ -15,6 +15,7 @@ import okhttp3.FormBody
 import okhttp3.OkHttpClient
 import okhttp3.Request
 import uy.kohesive.injekt.injectLazy
+import java.util.Locale
 
 class EHConfigurator(val context: Context) {
     private val prefs: PreferencesHelper by injectLazy()
@@ -64,7 +65,7 @@ class EHConfigurator(val context: Context) {
         val hathPerks = EHHathPerksResponse()
 
         perksPage.select(".stuffbox tr").forEach {
-            val name = it.child(0).text().toLowerCase()
+            val name = it.child(0).text().toLowerCase(Locale.getDefault())
             val purchased = it.child(2).getElementsByTag("form").isEmpty()
 
             when (name) {
diff --git a/app/src/main/java/exh/uconfig/EhUConfigBuilder.kt b/app/src/main/java/exh/uconfig/EhUConfigBuilder.kt
index a4c58196e..cff6af1aa 100644
--- a/app/src/main/java/exh/uconfig/EhUConfigBuilder.kt
+++ b/app/src/main/java/exh/uconfig/EhUConfigBuilder.kt
@@ -3,6 +3,7 @@ package exh.uconfig
 import eu.kanade.tachiyomi.data.preference.PreferencesHelper
 import okhttp3.FormBody
 import uy.kohesive.injekt.injectLazy
+import java.util.Locale
 
 class EhUConfigBuilder {
     private val preferences: PreferencesHelper by injectLazy()
@@ -13,7 +14,7 @@ class EhUConfigBuilder {
         configItems += when (
             preferences.imageQuality()
                 .get()
-                .toLowerCase()
+                .toLowerCase(Locale.getDefault())
         ) {
             "ovrs_2400" -> Entry.ImageSize.`2400`
             "ovrs_1600" -> Entry.ImageSize.`1600`
diff --git a/app/src/main/java/exh/ui/captcha/AutoSolvingWebViewClient.kt b/app/src/main/java/exh/ui/captcha/AutoSolvingWebViewClient.kt
index 151478d9e..c4e8db615 100644
--- a/app/src/main/java/exh/ui/captcha/AutoSolvingWebViewClient.kt
+++ b/app/src/main/java/exh/ui/captcha/AutoSolvingWebViewClient.kt
@@ -6,7 +6,6 @@ import android.webkit.WebView
 import eu.kanade.tachiyomi.util.asJsoup
 import org.jsoup.nodes.DataNode
 import org.jsoup.nodes.Element
-import java.nio.charset.Charset
 
 class AutoSolvingWebViewClient(
     activity: BrowserActionActivity,
@@ -27,7 +26,7 @@ class AutoSolvingWebViewClient(
             return WebResourceResponse(
                 "text/html",
                 "UTF-8",
-                doc.toString().byteInputStream(Charset.forName("UTF-8")).buffered()
+                doc.toString().byteInputStream().buffered()
             )
         }
         return super.shouldInterceptRequest(view, request)
diff --git a/app/src/main/java/exh/ui/login/LoginController.kt b/app/src/main/java/exh/ui/login/LoginController.kt
index ac7c7c3f8..b95192dd1 100755
--- a/app/src/main/java/exh/ui/login/LoginController.kt
+++ b/app/src/main/java/exh/ui/login/LoginController.kt
@@ -18,6 +18,7 @@ import eu.kanade.tachiyomi.util.system.setDefaultSettings
 import exh.uconfig.WarnConfigureDialogController
 import uy.kohesive.injekt.injectLazy
 import java.net.HttpCookie
+import java.util.Locale
 
 /**
  * LoginController
@@ -147,7 +148,7 @@ class LoginController : NucleusController<EhActivityLoginBinding, LoginPresenter
             var igneous: String? = null
 
             parsed.forEach {
-                when (it.name.toLowerCase()) {
+                when (it.name.toLowerCase(Locale.getDefault())) {
                     MEMBER_ID_COOKIE -> memberId = it.value
                     PASS_HASH_COOKIE -> passHash = it.value
                     IGNEOUS_COOKIE -> igneous = it.value
diff --git a/app/src/main/java/exh/util/DatabaseExtensions.kt b/app/src/main/java/exh/util/DatabaseExtensions.kt
index ff1422bd4..57978b79f 100644
--- a/app/src/main/java/exh/util/DatabaseExtensions.kt
+++ b/app/src/main/java/exh/util/DatabaseExtensions.kt
@@ -9,18 +9,10 @@ import com.pushtorefresh.storio.sqlite.operations.put.PutResults
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 
-suspend fun <T> PreparedGetListOfObjects<T>.executeOnIO(): List<T> {
-    return withContext(Dispatchers.IO) { executeAsBlocking() }
-}
+suspend fun <T> PreparedGetListOfObjects<T>.executeOnIO(): List<T> = withContext(Dispatchers.IO) { executeAsBlocking() }
 
-suspend fun <T> PreparedGetObject<T>.executeOnIO(): T? {
-    return withContext(Dispatchers.IO) { executeAsBlocking() }
-}
+suspend fun <T> PreparedGetObject<T>.executeOnIO(): T? = withContext(Dispatchers.IO) { executeAsBlocking() }
 
-suspend fun <T> PreparedPutObject<T>.executeOnIO(): PutResult {
-    return withContext(Dispatchers.IO) { executeAsBlocking() }
-}
+suspend fun <T> PreparedPutObject<T>.executeOnIO(): PutResult = withContext(Dispatchers.IO) { executeAsBlocking() }
 
-suspend fun <T> PreparedPutCollectionOfObjects<T>.executeOnIO(): PutResults<T> {
-    return withContext(Dispatchers.IO) { executeAsBlocking() }
-}
+suspend fun <T> PreparedPutCollectionOfObjects<T>.executeOnIO(): PutResults<T> = withContext(Dispatchers.IO) { executeAsBlocking() }