diff --git a/app/build.gradle b/app/build.gradle
index fd4ef939f..3c4ae917f 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -16,7 +16,7 @@ android {
 		minSdkVersion 21
 		targetSdkVersion 30
 		versionCode gitCommits
-		versionName '0.5.2'
+		versionName '0.5.3'
 
 		kapt {
 			arguments {
diff --git a/app/src/main/java/org/koitharu/kotatsu/core/local/WritableCbzFile.kt b/app/src/main/java/org/koitharu/kotatsu/core/local/WritableCbzFile.kt
new file mode 100644
index 000000000..8ddbf6631
--- /dev/null
+++ b/app/src/main/java/org/koitharu/kotatsu/core/local/WritableCbzFile.kt
@@ -0,0 +1,93 @@
+package org.koitharu.kotatsu.core.local
+
+import androidx.annotation.CheckResult
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import java.io.File
+import java.io.FileInputStream
+import java.io.FileOutputStream
+import java.util.zip.ZipEntry
+import java.util.zip.ZipInputStream
+import java.util.zip.ZipOutputStream
+
+class WritableCbzFile(private val file: File) {
+
+	private val dir = File(file.parentFile, file.nameWithoutExtension)
+
+	@Suppress("BlockingMethodInNonBlockingContext")
+	suspend fun prepare() = withContext(Dispatchers.IO) {
+		check(dir.list().isNullOrEmpty()) {
+			"Dir ${dir.name} is not empty"
+		}
+		if (!dir.exists()) {
+			dir.mkdir()
+		}
+		ZipInputStream(FileInputStream(file)).use { zip ->
+			var entry = zip.nextEntry
+			while (entry != null) {
+				val target = File(dir.path + File.separator + entry.name)
+				target.parentFile?.mkdirs()
+				target.outputStream().use { out ->
+					zip.copyTo(out)
+				}
+				zip.closeEntry()
+				entry = zip.nextEntry
+			}
+		}
+	}
+
+	suspend fun cleanup() = withContext(Dispatchers.IO) {
+		dir.deleteRecursively()
+	}
+
+	@CheckResult
+	@Suppress("BlockingMethodInNonBlockingContext")
+	suspend fun flush() = withContext(Dispatchers.IO) {
+		val tempFile = File(file.path + ".tmp")
+		if (tempFile.exists()) {
+			tempFile.delete()
+		}
+		try {
+			ZipOutputStream(FileOutputStream(tempFile)).use { zip ->
+				dir.listFiles()?.forEach {
+					zipFile(it, it.name, zip)
+				}
+				zip.flush()
+			}
+			tempFile.renameTo(file)
+		} finally {
+			if (tempFile.exists()) {
+				tempFile.delete()
+			}
+		}
+	}
+
+	operator fun get(name: String) = File(dir, name)
+
+	operator fun set(name: String, file: File) {
+		file.copyTo(this[name], overwrite = true)
+	}
+
+	companion object {
+
+		private fun zipFile(fileToZip: File, fileName: String, zipOut: ZipOutputStream) {
+			if (fileToZip.isDirectory) {
+				if (fileName.endsWith("/")) {
+					zipOut.putNextEntry(ZipEntry(fileName))
+				} else {
+					zipOut.putNextEntry(ZipEntry("$fileName/"))
+				}
+				zipOut.closeEntry()
+				fileToZip.listFiles()?.forEach { childFile ->
+					zipFile(childFile, "$fileName/${childFile.name}", zipOut)
+				}
+			} else {
+				FileInputStream(fileToZip).use { fis ->
+					val zipEntry = ZipEntry(fileName)
+					zipOut.putNextEntry(zipEntry)
+					fis.copyTo(zipOut)
+				}
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/app/src/main/java/org/koitharu/kotatsu/domain/local/MangaZip.kt b/app/src/main/java/org/koitharu/kotatsu/domain/local/MangaZip.kt
index 8a48d40d9..b6672aa31 100644
--- a/app/src/main/java/org/koitharu/kotatsu/domain/local/MangaZip.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/domain/local/MangaZip.kt
@@ -1,63 +1,35 @@
 package org.koitharu.kotatsu.domain.local
 
+import androidx.annotation.CheckResult
 import androidx.annotation.WorkerThread
+import org.koitharu.kotatsu.core.local.WritableCbzFile
 import org.koitharu.kotatsu.core.model.Manga
 import org.koitharu.kotatsu.core.model.MangaChapter
-import org.koitharu.kotatsu.utils.ext.sub
 import org.koitharu.kotatsu.utils.ext.takeIfReadable
 import org.koitharu.kotatsu.utils.ext.toFileNameSafe
 import java.io.File
-import java.util.zip.ZipEntry
-import java.util.zip.ZipInputStream
-import java.util.zip.ZipOutputStream
 
 @WorkerThread
 class MangaZip(val file: File) {
 
-	private val dir = file.parentFile?.sub(file.name + ".tmp")?.takeIf { it.mkdir() }
-		?: throw RuntimeException("Cannot create temporary directory")
+	private val writableCbz = WritableCbzFile(file)
 
 	private var index = MangaIndex(null)
 
-	fun prepare(manga: Manga) {
-		extract()
-		index = MangaIndex(dir.sub(INDEX_ENTRY).takeIfReadable()?.readText())
+	suspend fun prepare(manga: Manga) {
+		writableCbz.prepare()
+		index = MangaIndex(writableCbz[INDEX_ENTRY].takeIfReadable()?.readText())
 		index.setMangaInfo(manga, append = true)
 	}
 
-	fun cleanup() {
-		dir.deleteRecursively()
+	suspend fun cleanup() {
+		writableCbz.cleanup()
 	}
 
-	fun compress() {
-		dir.sub(INDEX_ENTRY).writeText(index.toString())
-		ZipOutputStream(file.outputStream()).use { out ->
-			for (file in dir.listFiles().orEmpty()) {
-				val entry = ZipEntry(file.name)
-				out.putNextEntry(entry)
-				file.inputStream().use { stream ->
-					stream.copyTo(out)
-				}
-				out.closeEntry()
-			}
-		}
-	}
-
-	private fun extract() {
-		if (!file.exists()) {
-			return
-		}
-		ZipInputStream(file.inputStream()).use { input ->
-			while (true) {
-				val entry = input.nextEntry ?: return
-				if (!entry.isDirectory) {
-					dir.sub(entry.name).outputStream().use { out ->
-						input.copyTo(out)
-					}
-				}
-				input.closeEntry()
-			}
-		}
+	@CheckResult
+	suspend fun compress(): Boolean {
+		writableCbz[INDEX_ENTRY].writeText(index.toString())
+		return writableCbz.flush()
 	}
 
 	fun addCover(file: File, ext: String) {
@@ -68,7 +40,7 @@ class MangaZip(val file: File) {
 				append(ext)
 			}
 		}
-		file.copyTo(dir.sub(name), overwrite = true)
+		writableCbz[name] = file
 		index.setCoverEntry(name)
 	}
 
@@ -80,7 +52,7 @@ class MangaZip(val file: File) {
 				append(ext)
 			}
 		}
-		file.copyTo(dir.sub(name), overwrite = true)
+		writableCbz[name] = file
 		index.addChapter(chapter)
 	}
 
diff --git a/app/src/main/java/org/koitharu/kotatsu/ui/download/DownloadService.kt b/app/src/main/java/org/koitharu/kotatsu/ui/download/DownloadService.kt
index 9e596ad8b..776af0ee0 100644
--- a/app/src/main/java/org/koitharu/kotatsu/ui/download/DownloadService.kt
+++ b/app/src/main/java/org/koitharu/kotatsu/ui/download/DownloadService.kt
@@ -142,7 +142,9 @@ class DownloadService : BaseService() {
 				notification.setCancelId(0)
 				notification.setPostProcessing()
 				notification.update()
-				output.compress()
+				if (!output.compress()) {
+					throw RuntimeException("Cannot create target file")
+				}
 				val result = MangaProviderFactory.createLocal().getFromFile(output.file)
 				notification.setDone(result)
 				notification.dismiss()