diff --git a/app/src/main/java/im/conversations/android/transformer/Transformer.java b/app/src/main/java/im/conversations/android/transformer/Transformer.java
index 421e06b0c..8e2ef90de 100644
--- a/app/src/main/java/im/conversations/android/transformer/Transformer.java
+++ b/app/src/main/java/im/conversations/android/transformer/Transformer.java
@@ -94,7 +94,8 @@ public class Transformer {
             try {
                 final var payload = axolotlService.decrypt(transformation.from, encrypted);
                 if (payload.hasPayload()) {
-                    contents = ImmutableList.of(MessageContent.text(payload.payloadAsString(),null));
+                    contents =
+                            ImmutableList.of(MessageContent.text(payload.payloadAsString(), null));
                 } else {
                     return true;
                 }
diff --git a/app/src/main/java/im/conversations/android/xmpp/manager/AbstractManager.java b/app/src/main/java/im/conversations/android/xmpp/manager/AbstractManager.java
index 9bde1e7a6..e75227a25 100644
--- a/app/src/main/java/im/conversations/android/xmpp/manager/AbstractManager.java
+++ b/app/src/main/java/im/conversations/android/xmpp/manager/AbstractManager.java
@@ -7,7 +7,8 @@ import java.util.concurrent.Executors;
 
 public class AbstractManager extends XmppConnection.Delegate {
 
-    protected static final Executor IO_EXECUTOR = Executors.newSingleThreadExecutor();
+    protected static final Executor FILE_IO_EXECUTOR = Executors.newSingleThreadExecutor();
+    protected static final Executor CPU_EXECUTOR = Executors.newSingleThreadExecutor();
 
     protected AbstractManager(final Context context, final XmppConnection connection) {
         super(context, connection);
diff --git a/app/src/main/java/im/conversations/android/xmpp/manager/AvatarManager.java b/app/src/main/java/im/conversations/android/xmpp/manager/AvatarManager.java
index 68a4a2a85..c8e50e5b0 100644
--- a/app/src/main/java/im/conversations/android/xmpp/manager/AvatarManager.java
+++ b/app/src/main/java/im/conversations/android/xmpp/manager/AvatarManager.java
@@ -101,7 +101,8 @@ public class AvatarManager extends AbstractManager {
     }
 
     private ListenableFuture<byte[]> getCachedOrFetch(final Jid address, final String id) {
-        final var cachedFuture = Futures.submit(() -> getCachedAvatar(address, id), IO_EXECUTOR);
+        final var cachedFuture =
+                Futures.submit(() -> getCachedAvatar(address, id), FILE_IO_EXECUTOR);
         return Futures.catchingAsync(
                 cachedFuture,
                 Exception.class,
@@ -133,7 +134,7 @@ public class AvatarManager extends AbstractManager {
                     }
                     throw new IllegalStateException("Avatar sha1hash did not match expected value");
                 },
-                IO_EXECUTOR);
+                FILE_IO_EXECUTOR);
     }
 
     private File getCacheFile(final Jid address, final String id) {
diff --git a/app/src/main/java/im/conversations/android/xmpp/manager/AxolotlManager.java b/app/src/main/java/im/conversations/android/xmpp/manager/AxolotlManager.java
index e152673e2..079096c30 100644
--- a/app/src/main/java/im/conversations/android/xmpp/manager/AxolotlManager.java
+++ b/app/src/main/java/im/conversations/android/xmpp/manager/AxolotlManager.java
@@ -265,8 +265,7 @@ public class AxolotlManager extends AbstractManager {
     }
 
     private ListenableFuture<Void> publishBundle() {
-        final ListenableFuture<Bundle> bundleFuture =
-                Futures.submit(this::prepareBundle, IO_EXECUTOR);
+        final ListenableFuture<Bundle> bundleFuture = prepareBundle();
         return Futures.transformAsync(
                 bundleFuture,
                 bundle -> {
@@ -282,8 +281,13 @@ public class AxolotlManager extends AbstractManager {
                 MoreExecutors.directExecutor());
     }
 
-    private Bundle prepareBundle() {
-        refillPreKeys();
+    private ListenableFuture<Bundle> prepareBundle() {
+        final var refillFuture = Futures.submit(this::refillPreKeys, CPU_EXECUTOR);
+        return Futures.transform(
+                refillFuture, this::prepareBundle, getDatabase().getQueryExecutor());
+    }
+
+    private Bundle prepareBundle(Void v) {
         final var bundle = new Bundle();
         bundle.setIdentityKey(
                 signalProtocolStore().getIdentityKeyPair().getPublicKey().getPublicKey());