diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 1a3bc37..2b4ea6f 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -19,7 +19,7 @@ jobs:
     name: Ruby ${{ matrix.ruby }} - PG ${{ matrix.pg.from }} -> PG ${{ matrix.pg.to }}
     strategy:
       matrix:
-        ruby: ["3.0.5", "3.1.4", "3.2.1"]
+        ruby: ["3.0.5", "3.1.4", "3.2.1", "3.3.6"]
         pg:
           [
             { from: 10, to: 11 },
diff --git a/.github/workflows/smoke.yaml b/.github/workflows/smoke.yaml
index 142c5ea..195fdca 100644
--- a/.github/workflows/smoke.yaml
+++ b/.github/workflows/smoke.yaml
@@ -19,7 +19,7 @@ jobs:
     name: Ruby ${{ matrix.ruby }} - PG ${{ matrix.pg.from }} -> PG ${{ matrix.pg.to }}
     strategy:
       matrix:
-        ruby: ["3.0.5", "3.1.4", "3.2.1"]
+        ruby: ["3.0.5", "3.1.4", "3.2.1", "3.3.6"]
         pg:
           [
             { from: 10, to: 11 },
diff --git a/.ruby-version b/.ruby-version
index 0aec50e..9c25013 100644
--- a/.ruby-version
+++ b/.ruby-version
@@ -1 +1 @@
-3.1.4
+3.3.6
diff --git a/Dockerfile b/Dockerfile
index ef2f029..6b067f2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,22 @@
-FROM ruby:3.1.4
+FROM ruby:3.1.4-slim
 
 ARG VERSION
 
-RUN apt-get update && apt-get install postgresql-client -y
+RUN apt-get update && \
+  apt-get install -y --no-install-recommends \
+  wget \
+  gnupg2 \
+  lsb-release \
+  build-essential \
+  libpq-dev \
+  && wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | gpg --dearmor -o /usr/share/keyrings/postgresql-keyring.gpg && \
+  echo "deb [signed-by=/usr/share/keyrings/postgresql-keyring.gpg] http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list && \
+  apt-get update && \
+  apt-get install -y --no-install-recommends postgresql-client && \
+  gem install pg_easy_replicate -v $VERSION && \
+  apt-get remove -y wget gnupg2 lsb-release && \
+  apt-get autoremove -y && \
+  apt-get clean && \
+  rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
+
 RUN pg_dump --version
-RUN gem install pg_easy_replicate -v $VERSION
diff --git a/Gemfile.lock b/Gemfile.lock
index 937d40b..4e07f45 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    pg_easy_replicate (0.3.7)
+    pg_easy_replicate (0.3.8)
       ougai (~> 2.0.0)
       pg (~> 1.5.3)
       pg_query (~> 5.1.0)
diff --git a/README.md b/README.md
index ae29f5f..335dd09 100644
--- a/README.md
+++ b/README.md
@@ -374,5 +374,5 @@ Next, you can set up a program that watches the `stats` and waits until `switcho
 PRs most welcome. You can get started locally by
 
 - `docker compose down -v && docker compose up --remove-orphans --build`
-- Install ruby `3.1.4` using RVM ([instruction](https://rvm.io/rvm/install#any-other-system))
+- Install ruby `3.3.6` using RVM ([instruction](https://rvm.io/rvm/install#any-other-system))
 - `bundle exec rspec` for specs
diff --git a/lib/pg_easy_replicate/version.rb b/lib/pg_easy_replicate/version.rb
index 38b2600..03bcd49 100644
--- a/lib/pg_easy_replicate/version.rb
+++ b/lib/pg_easy_replicate/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module PgEasyReplicate
-  VERSION = "0.3.7"
+  VERSION = "0.3.8"
 end