diff --git a/src/Simplex/Chat.hs b/src/Simplex/Chat.hs
index 585b039ca6..5c56c788c5 100644
--- a/src/Simplex/Chat.hs
+++ b/src/Simplex/Chat.hs
@@ -121,7 +121,7 @@ defaultChatConfig =
           },
       dbPoolSize = 1,
       tbqSize = 16,
-      fileChunkSize = 15000
+      fileChunkSize = 15780
     }
 
 logCfg :: LogConfig
diff --git a/stack.yaml b/stack.yaml
index 309b073e12..c6c9cf0fde 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -41,7 +41,7 @@ extra-deps:
   # - simplexmq-0.5.2@sha256:3544e479f353c1bbc6aa9405ef6976b78364f437d8af9cc45b9e0b228429e240,7884
   # - ../simplexmq
   - github: simplex-chat/simplexmq
-    commit: d8a61de290207509dc57a548f5551e294066e040
+    commit: 5f20f0124a16a5b20ef9dba28d5d9cdb84290afd
   - github: simplex-chat/hs-tls
     commit: cea6d52c512716ff09adcac86ebc95bb0b3bb797
     subdirs: