diff --git a/src/main/kotlin/mdnet/MangaDexClient.kt b/src/main/kotlin/mdnet/MangaDexClient.kt
index ad40187..c6f498c 100644
--- a/src/main/kotlin/mdnet/MangaDexClient.kt
+++ b/src/main/kotlin/mdnet/MangaDexClient.kt
@@ -70,7 +70,6 @@ class MangaDexClient(private val settingsFile: File, databaseFolder: Path, cache
         val config = HikariConfig()
         val db = databaseFolder.resolve("metadata.db")
         config.jdbcUrl = "jdbc:sqlite:$db"
-        config.maximumPoolSize = 1
         config.addDataSourceProperty("cachePrepStmts", "true")
         config.addDataSourceProperty("prepStmtCacheSize", "100")
         config.addDataSourceProperty("prepStmtCacheSqlLimit", "1000")
diff --git a/src/main/kotlin/mdnet/cache/ImageStorage.kt b/src/main/kotlin/mdnet/cache/ImageStorage.kt
index 7e0ba1d..69d2db6 100644
--- a/src/main/kotlin/mdnet/cache/ImageStorage.kt
+++ b/src/main/kotlin/mdnet/cache/ImageStorage.kt
@@ -31,7 +31,7 @@ import org.ktorm.dsl.*
 import org.slf4j.LoggerFactory
 import java.io.*
 import java.nio.file.*
-import java.sql.SQLIntegrityConstraintViolationException
+import java.sql.SQLException
 import java.time.Instant
 import java.util.UUID
 import java.util.concurrent.*
@@ -94,12 +94,14 @@ class ImageStorage(
                 val now = Instant.now()
 
                 LOGGER.info { "Updating LRU times for ${toUpdate.size} entries" }
-                database.batchUpdate(DbImage) {
-                    for (id in toUpdate) {
-                        item {
-                            set(DbImage.accessed, now)
-                            where {
-                                DbImage.id eq id
+                synchronized(database) {
+                    database.batchUpdate(DbImage) {
+                        for (id in toUpdate) {
+                            item {
+                                set(DbImage.accessed, now)
+                                where {
+                                    DbImage.id eq id
+                                }
                             }
                         }
                     }
@@ -218,20 +220,20 @@ class ImageStorage(
     private fun deleteImage(id: String) {
         LOGGER.trace { "Deleting image $id from cache" }
 
-        database.useTransaction {
-            val path = getTempPath()
+        val path = getTempPath()
 
-            try {
-                Files.move(
-                    getPath(id),
-                    path,
-                    StandardCopyOption.ATOMIC_MOVE
-                )
+        try {
+            Files.move(
+                getPath(id),
+                path,
+                StandardCopyOption.ATOMIC_MOVE
+            )
 
-                Files.deleteIfExists(path)
-            } catch (e: IOException) {
-                // a failure means the image did not exist
-            } finally {
+            Files.deleteIfExists(path)
+        } catch (e: IOException) {
+            // a failure means the image did not exist
+        } finally {
+            synchronized(database) {
                 database.delete(DbImage) {
                     DbImage.id eq id
                 }
@@ -312,12 +314,14 @@ class ImageStorage(
             Files.createDirectories(getPath(id).parent)
 
             try {
-                database.insert(DbImage) {
-                    set(DbImage.id, id)
-                    set(DbImage.accessed, Instant.now())
-                    set(DbImage.size, metadataSize + bytes)
+                synchronized(database) {
+                    database.insert(DbImage) {
+                        set(DbImage.id, id)
+                        set(DbImage.accessed, Instant.now())
+                        set(DbImage.size, metadataSize + bytes)
+                    }
                 }
-            } catch (e: SQLIntegrityConstraintViolationException) {
+            } catch (e: SQLException) {
                 // someone got to us before this (TOCTOU)
                 // there are 2 situations here
                 // one is that the