diff --git a/uhabits-android/build.gradle.kts b/uhabits-android/build.gradle.kts
index 201ddf7f..d546c3eb 100644
--- a/uhabits-android/build.gradle.kts
+++ b/uhabits-android/build.gradle.kts
@@ -95,6 +95,8 @@ android {
 
 mokkery {
     defaultMockMode.set(dev.mokkery.MockMode.autofill)
+    stubs.allowClassInheritance.set(true)
+    stubs.allowConcreteClassInstantiation.set(true)
 }
 
 dependencies {
diff --git a/uhabits-android/src/main/java/org/isoron/uhabits/tasks/AndroidTaskRunner.kt b/uhabits-android/src/main/java/org/isoron/uhabits/tasks/AndroidTaskRunner.kt
index 4d3b2b9d..018c7649 100644
--- a/uhabits-android/src/main/java/org/isoron/uhabits/tasks/AndroidTaskRunner.kt
+++ b/uhabits-android/src/main/java/org/isoron/uhabits/tasks/AndroidTaskRunner.kt
@@ -19,6 +19,7 @@
 package org.isoron.uhabits.tasks
 
 import android.os.AsyncTask
+import kotlinx.coroutines.runBlocking
 import org.isoron.uhabits.core.tasks.Task
 import org.isoron.uhabits.core.tasks.TaskRunner
 import java.util.HashMap
@@ -58,7 +59,7 @@ class AndroidTaskRunner : TaskRunner {
         @Deprecated("Deprecated in Java")
         override fun doInBackground(vararg params: Void?): Void? {
             if (isCancelled) return null
-            task.doInBackground()
+            runBlocking { task.doInBackground() }
             return null
         }
 
diff --git a/uhabits-android/src/main/java/org/isoron/uhabits/tasks/ExportDBTask.kt b/uhabits-android/src/main/java/org/isoron/uhabits/tasks/ExportDBTask.kt
index 3804e885..1621b714 100644
--- a/uhabits-android/src/main/java/org/isoron/uhabits/tasks/ExportDBTask.kt
+++ b/uhabits-android/src/main/java/org/isoron/uhabits/tasks/ExportDBTask.kt
@@ -35,7 +35,7 @@ class ExportDBTask(
     private val listener: Listener
 ) : Task {
     private var filename: String? = null
-    override fun doInBackground() {
+    override suspend fun doInBackground() {
         filename = null
         filename = try {
             val prefs = PreferenceManager.getDefaultSharedPreferences(context)
diff --git a/uhabits-android/src/main/java/org/isoron/uhabits/tasks/ImportDataTask.kt b/uhabits-android/src/main/java/org/isoron/uhabits/tasks/ImportDataTask.kt
index 699ba99b..6a410188 100644
--- a/uhabits-android/src/main/java/org/isoron/uhabits/tasks/ImportDataTask.kt
+++ b/uhabits-android/src/main/java/org/isoron/uhabits/tasks/ImportDataTask.kt
@@ -19,7 +19,6 @@
 package org.isoron.uhabits.tasks
 
 import android.util.Log
-import kotlinx.coroutines.runBlocking
 import org.isoron.platform.io.UserFile
 import org.isoron.platform.io.begin
 import org.isoron.platform.io.commit
@@ -36,18 +35,16 @@ class ImportDataTask(
 ) : Task {
     private var result = 0
     private val modelFactory: SQLModelFactory = modelFactory as SQLModelFactory
-    override fun doInBackground() {
+    override suspend fun doInBackground() {
         modelFactory.database.begin()
         try {
-            runBlocking {
-                if (importer.canHandle(file)) {
-                    importer.importHabitsFromFile(file)
-                    result = SUCCESS
-                    modelFactory.database.commit()
-                } else {
-                    result = NOT_RECOGNIZED
-                    modelFactory.database.commit()
-                }
+            if (importer.canHandle(file)) {
+                importer.importHabitsFromFile(file)
+                result = SUCCESS
+                modelFactory.database.commit()
+            } else {
+                result = NOT_RECOGNIZED
+                modelFactory.database.commit()
             }
         } catch (e: Exception) {
             result = FAILED
diff --git a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/commands/CommandRunner.kt b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/commands/CommandRunner.kt
index 84f15e3c..7aa4a588 100644
--- a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/commands/CommandRunner.kt
+++ b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/commands/CommandRunner.kt
@@ -33,7 +33,7 @@ open class CommandRunner(
     open fun run(command: Command) {
         taskRunner.execute(
             object : Task {
-                override fun doInBackground() {
+                override suspend fun doInBackground() {
                     command.run()
                 }
                 override fun onPostExecute() {
diff --git a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/models/HabitList.kt b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/models/HabitList.kt
index e56dbf87..58d5b58a 100644
--- a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/models/HabitList.kt
+++ b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/models/HabitList.kt
@@ -197,7 +197,9 @@ abstract class HabitList : Iterable<Habit> {
                 if (habit.isNumerical) {
                     val s = habit.targetValue.toString()
                     if ('.' !in s) "$s.0" else s
-                } else "",
+                } else {
+                    ""
+                },
                 habit.isArchived.toString()
             )
             sb.append(csvLine(cols))
diff --git a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/ExportCSVTask.kt b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/ExportCSVTask.kt
index 76c0559c..c04d9c10 100644
--- a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/ExportCSVTask.kt
+++ b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/ExportCSVTask.kt
@@ -19,7 +19,6 @@
 package org.isoron.uhabits.core.tasks
 
 import org.isoron.platform.io.UserFile
-import org.isoron.platform.runSuspend
 import org.isoron.platform.time.getToday
 import org.isoron.uhabits.core.io.HabitsCSVExporter
 import org.isoron.uhabits.core.models.Habit
@@ -32,13 +31,13 @@ class ExportCSVTask(
     private val listener: ExportCSVListener
 ) : Task {
     private var archiveFilename: String? = null
-    override fun doInBackground() {
+    override suspend fun doInBackground() {
         try {
             val exporter = HabitsCSVExporter(habitList, selectedHabits)
-            val bytes = runSuspend { exporter.writeArchive() }
+            val bytes = exporter.writeArchive()
             val date = getToday().toCSVString()
             val zipFile = outputDir.resolve("Loop Habits CSV $date.zip")
-            runSuspend { zipFile.writeBytes(bytes) }
+            zipFile.writeBytes(bytes)
             archiveFilename = zipFile.pathString
         } catch (e: Exception) {
             e.printStackTrace()
diff --git a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.kt b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.kt
index 6b1aed1f..36973188 100644
--- a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.kt
+++ b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/SingleThreadTaskRunner.kt
@@ -18,6 +18,8 @@
  */
 package org.isoron.uhabits.core.tasks
 
+import org.isoron.platform.runSuspend
+
 class SingleThreadTaskRunner : TaskRunner {
     override val activeTaskCount: Int
         get() = 0
@@ -32,7 +34,7 @@ class SingleThreadTaskRunner : TaskRunner {
         if (!task.isCanceled()) {
             task.onAttached(this)
             task.onPreExecute()
-            task.doInBackground()
+            runSuspend { task.doInBackground() }
             task.onPostExecute()
         }
         for (l in listeners) l.onTaskFinished(task)
diff --git a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/Task.kt b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/Task.kt
index d2b4ba7f..7c802a33 100644
--- a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/Task.kt
+++ b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/tasks/Task.kt
@@ -21,7 +21,7 @@ package org.isoron.uhabits.core.tasks
 fun interface Task {
     fun cancel() {}
     fun isCanceled() = false
-    fun doInBackground()
+    suspend fun doInBackground()
     fun onAttached(runner: TaskRunner) {}
     fun onPostExecute() {}
     fun onPreExecute() {}
diff --git a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/ui/NotificationTray.kt b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/ui/NotificationTray.kt
index afd303b6..2cf63940 100644
--- a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/ui/NotificationTray.kt
+++ b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/ui/NotificationTray.kt
@@ -113,7 +113,7 @@ open class NotificationTray(
         private val date: LocalDate = data.date
         private val reminderTime: Long = data.reminderTime
 
-        override fun doInBackground() {
+        override suspend fun doInBackground() {
             isCompleted = habit.isCompletedToday()
         }
 
diff --git a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/ui/screens/habits/list/HabitCardListCache.kt b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/ui/screens/habits/list/HabitCardListCache.kt
index b7ef20a7..e71cb292 100644
--- a/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/ui/screens/habits/list/HabitCardListCache.kt
+++ b/uhabits-core/src/commonMain/kotlin/org/isoron/uhabits/core/ui/screens/habits/list/HabitCardListCache.kt
@@ -292,7 +292,7 @@ class HabitCardListCache(
         }
 
         @Synchronized
-        override fun doInBackground() {
+        override suspend fun doInBackground() {
             newData.fetchHabits()
             newData.copyScoresFrom(data)
             newData.copyCheckmarksFrom(data)
diff --git a/uhabits-core/src/commonTest/kotlin/org/isoron/uhabits/core/tasks/SingleThreadTaskRunnerTest.kt b/uhabits-core/src/commonTest/kotlin/org/isoron/uhabits/core/tasks/SingleThreadTaskRunnerTest.kt
index 97cb93b3..03757a8c 100644
--- a/uhabits-core/src/commonTest/kotlin/org/isoron/uhabits/core/tasks/SingleThreadTaskRunnerTest.kt
+++ b/uhabits-core/src/commonTest/kotlin/org/isoron/uhabits/core/tasks/SingleThreadTaskRunnerTest.kt
@@ -19,8 +19,8 @@
 package org.isoron.uhabits.core.tasks
 
 import dev.mokkery.mock
-import dev.mokkery.verify
 import dev.mokkery.verify.VerifyMode.Companion.order
+import dev.mokkery.verifySuspend
 import org.isoron.uhabits.core.BaseUnitTest
 import kotlin.test.BeforeTest
 import kotlin.test.Test
@@ -38,7 +38,7 @@ class SingleThreadTaskRunnerTest : BaseUnitTest() {
     @Test
     fun test() {
         runner.execute(task)
-        verify(order) {
+        verifySuspend(order) {
             task.onAttached(runner)
             task.onPreExecute()
             task.doInBackground()
diff --git a/uhabits-core/src/jsMain/kotlin/org/isoron/platform/io/JsZipReader.kt b/uhabits-core/src/jsMain/kotlin/org/isoron/platform/io/ZipReader.kt
similarity index 100%
rename from uhabits-core/src/jsMain/kotlin/org/isoron/platform/io/JsZipReader.kt
rename to uhabits-core/src/jsMain/kotlin/org/isoron/platform/io/ZipReader.kt
diff --git a/uhabits-core/src/jsMain/kotlin/org/isoron/platform/io/JsZipWriter.kt b/uhabits-core/src/jsMain/kotlin/org/isoron/platform/io/ZipWriter.kt
similarity index 100%
rename from uhabits-core/src/jsMain/kotlin/org/isoron/platform/io/JsZipWriter.kt
rename to uhabits-core/src/jsMain/kotlin/org/isoron/platform/io/ZipWriter.kt