diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8dca73fb4a..57801b969b 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,11 +4,16 @@ All notable changes to this project are documented below.
 The format is based on [keep a changelog](http://keepachangelog.com) and this project uses [semantic versioning](http://semver.org).
 
 ## [Unreleased]
+### Changed
+- Improve handling of messages being sent while session is closing.
+- Build with Go 1.21.6.
+
 ### Fixed
 - Skip Google refund handling for deleted users.
 - Fix storage engine version check regression.
-- Fix JS runtime tournament records list owner ids param.
+- Fix JavaScript runtime tournament records list owner identifier parameter handling.
 - Fix regression in tournament end active time calculation when it coincides with reset schedule.
+- Better handling of concurrent wallet update operations for the same user.
 
 ## [3.20.0] - 2023-12-15
 ### Changed
diff --git a/build/Dockerfile b/build/Dockerfile
index 45f80558b0..6e66407ee1 100644
--- a/build/Dockerfile
+++ b/build/Dockerfile
@@ -15,7 +15,7 @@
 # docker build "$PWD" --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version=v2.1.1 -t heroiclabs/nakama:2.1.1
 # docker build "$PWD" --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version="$(git rev-parse --short HEAD)" -t heroiclabs/nakama-prerelease:"$(git rev-parse --short HEAD)"
 
-FROM golang:1.21.5-bookworm as builder
+FROM golang:1.21.6-bookworm as builder
 
 ARG commit
 ARG version
diff --git a/build/Dockerfile.arm64 b/build/Dockerfile.arm64
index 2201825b77..414de0b178 100644
--- a/build/Dockerfile.arm64
+++ b/build/Dockerfile.arm64
@@ -15,7 +15,7 @@
 # docker build "$PWD" --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version=v2.1.1 -t heroiclabs/nakama:2.1.1
 # docker build "$PWD" --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version="$(git rev-parse --short HEAD)" -t heroiclabs/nakama-prerelease:"$(git rev-parse --short HEAD)"
 
-FROM arm64v8/golang:1.21.5-bookworm as builder
+FROM arm64v8/golang:1.21.6-bookworm as builder
 
 ARG commit
 ARG version
diff --git a/build/Dockerfile.dsym b/build/Dockerfile.dsym
index 72c357cf73..5f7e480d60 100644
--- a/build/Dockerfile.dsym
+++ b/build/Dockerfile.dsym
@@ -15,7 +15,7 @@
 # docker build "$PWD" --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version=v3.19.0 -t heroiclabs/nakama:3.19.0
 # docker build "$PWD" --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version="v3.19.0-$(git rev-parse --short HEAD)" -t heroiclabs/nakama-prerelease:"3.19.0-$(git rev-parse --short HEAD)"
 
-FROM golang:1.21.5-bookworm as builder
+FROM golang:1.21.6-bookworm as builder
 
 ARG commit
 ARG version
diff --git a/build/Dockerfile.dsym.arm64 b/build/Dockerfile.dsym.arm64
index bac807215d..f77d0d0ac6 100644
--- a/build/Dockerfile.dsym.arm64
+++ b/build/Dockerfile.dsym.arm64
@@ -15,7 +15,7 @@
 # docker build "$PWD" --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version=v3.19.0 -t heroiclabs/nakama:3.19.0
 # docker build "$PWD" --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version="v3.19.0-$(git rev-parse --short HEAD)" -t heroiclabs/nakama-prerelease:"3.19.0-$(git rev-parse --short HEAD)"
 
-FROM arm64v8/golang:1.21.5-bookworm as builder
+FROM arm64v8/golang:1.21.6-bookworm as builder
 
 ARG commit
 ARG version
diff --git a/build/Dockerfile.local b/build/Dockerfile.local
index f7b5f6da88..a9e1f98f57 100644
--- a/build/Dockerfile.local
+++ b/build/Dockerfile.local
@@ -14,7 +14,7 @@
 
 # docker build .. -f Dockerfile.local -t nakama:dev
 
-FROM golang:1.21.5-bookworm as builder
+FROM golang:1.21.6-bookworm as builder
 
 ENV GOOS linux
 ENV CGO_ENABLED 1
diff --git a/build/pluginbuilder/Dockerfile b/build/pluginbuilder/Dockerfile
index 3ece9ae296..67b8f733aa 100644
--- a/build/pluginbuilder/Dockerfile
+++ b/build/pluginbuilder/Dockerfile
@@ -15,7 +15,7 @@
 # docker build . --file ./Dockerfile --build-arg version=v2.1.1 -t heroiclabs/nakama-pluginbuilder:2.1.1
 # docker build . --file ./Dockerfile --build-arg version="v2.1.1-$(git rev-parse --short HEAD)" -t heroiclabs/nakama-pluginbuilder:"2.1.1-$(git rev-parse --short HEAD)"
 
-FROM golang:1.21.5-bookworm as builder
+FROM golang:1.21.6-bookworm as builder
 
 MAINTAINER Heroic Labs <support@heroiclabs.com>
 
diff --git a/build/pluginbuilder/Dockerfile.arm64 b/build/pluginbuilder/Dockerfile.arm64
index 8637513c2d..287e7f802b 100644
--- a/build/pluginbuilder/Dockerfile.arm64
+++ b/build/pluginbuilder/Dockerfile.arm64
@@ -15,7 +15,7 @@
 # docker build "$PWD" --file ./Dockerfile.pluginbuilder --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version=v2.1.1 -t heroiclabs/nakama-pluginbuilder:2.1.1
 # docker build "$PWD" --file ./Dockerfile.pluginbuilder --build-arg commit="$(git rev-parse --short HEAD)" --build-arg version="v2.1.1-$(git rev-parse --short HEAD)" -t heroiclabs/nakama-prerelease:"2.1.1-$(git rev-parse --short HEAD)"
 
-FROM arm64v8/golang:1.21.5-bookworm as builder
+FROM arm64v8/golang:1.21.6-bookworm as builder
 
 MAINTAINER Heroic Labs <support@heroiclabs.com>
 
diff --git a/server/leaderboard_rank_cache.go b/server/leaderboard_rank_cache.go
index b174540026..5eab13044c 100644
--- a/server/leaderboard_rank_cache.go
+++ b/server/leaderboard_rank_cache.go
@@ -52,7 +52,11 @@ type RankAsc struct {
 }
 
 func (r RankAsc) Less(other interface{}) bool {
-	ro := other.(RankAsc)
+	ro, ok := other.(RankAsc)
+	if !ok {
+		return true
+	}
+
 	if r.Score < ro.Score {
 		return true
 	}
@@ -76,7 +80,11 @@ type RankDesc struct {
 }
 
 func (r RankDesc) Less(other interface{}) bool {
-	ro := other.(RankDesc)
+	ro, ok := other.(RankDesc)
+	if !ok {
+		return true
+	}
+
 	if ro.Score < r.Score {
 		return true
 	}