diff --git a/app/src/main/java/eu/faircode/email/SimpleTask.java b/app/src/main/java/eu/faircode/email/SimpleTask.java
index 6cd5b725fd..ad7b9c5202 100644
--- a/app/src/main/java/eu/faircode/email/SimpleTask.java
+++ b/app/src/main/java/eu/faircode/email/SimpleTask.java
@@ -49,7 +49,8 @@ public abstract class SimpleTask<T> implements LifecycleObserver {
     private String name;
     private Result stored;
 
-    private static ExecutorService executor = Executors.newCachedThreadPool(Helper.backgroundThreadFactory);
+    private static ExecutorService executor = Executors.newFixedThreadPool(
+            Runtime.getRuntime().availableProcessors(), Helper.backgroundThreadFactory);
 
     public void execute(Context context, LifecycleOwner owner, Bundle args, String name) {
         run(context, owner, args, name);