diff --git a/CHANGES.md b/CHANGES.md
index 75a030fd..3e855a20 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,4 +1,9 @@
 
+# 0.5.1
+
+- fix `Ws_pool`: workers would exit before processing
+    all remaining tasks upon shutdown
+
 # 0.5
 
 ## features
diff --git a/dune-project b/dune-project
index d82dfdc7..5c54caea 100644
--- a/dune-project
+++ b/dune-project
@@ -2,7 +2,7 @@
 (using mdx 0.2)
 
 (name moonpool)
-(version 0.5)
+(version 0.5.1)
 (generate_opam_files true)
 (source
  (github c-cube/moonpool))