diff --git a/.semaphore/semaphore.yml b/.semaphore/semaphore.yml
index 29f1faf72..e2d32b255 100644
--- a/.semaphore/semaphore.yml
+++ b/.semaphore/semaphore.yml
@@ -8,7 +8,7 @@ execution_time_limit:
 global_job_config:
   env_vars:
     - name: LIBRDKAFKA_VERSION
-      value: v2.5.3-RC1
+      value: v2.5.3
   prologue:
     commands:
       - checkout
diff --git a/docs/conf.py b/docs/conf.py
index dcdde4cc4..995176d5f 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -35,7 +35,7 @@
 # built documents.
 #
 # The short X.Y version.
-version = '2.5.3rc1'
+version = '2.5.3'
 # The full version, including alpha/beta/rc tags.
 release = version
 ######################################################################
diff --git a/examples/docker/Dockerfile.alpine b/examples/docker/Dockerfile.alpine
index 6bb4147b3..c50b87b6e 100644
--- a/examples/docker/Dockerfile.alpine
+++ b/examples/docker/Dockerfile.alpine
@@ -30,7 +30,7 @@ FROM alpine:3.12
 
 COPY . /usr/src/confluent-kafka-python
 
-ENV LIBRDKAFKA_VERSION v2.5.3-RC1
+ENV LIBRDKAFKA_VERSION v2.5.3
 ENV KAFKACAT_VERSION master
 
 
diff --git a/setup.py b/setup.py
index 8f2abb930..fe12df2d6 100755
--- a/setup.py
+++ b/setup.py
@@ -75,7 +75,7 @@ def get_install_requirements(path):
 setup(name='confluent-kafka',
       # Make sure to bump CFL_VERSION* in confluent_kafka/src/confluent_kafka.h
       # and version in docs/conf.py.
-      version='2.5.3rc1',
+      version='2.5.3',
       description='Confluent\'s Python client for Apache Kafka',
       author='Confluent Inc',
       author_email='support@confluent.io',
diff --git a/src/confluent_kafka/src/confluent_kafka.h b/src/confluent_kafka/src/confluent_kafka.h
index a78e56961..d6ad31635 100644
--- a/src/confluent_kafka/src/confluent_kafka.h
+++ b/src/confluent_kafka/src/confluent_kafka.h
@@ -43,7 +43,7 @@
  *  MM=major, mm=minor, RR=revision, PP=patchlevel (not used)
  */
 #define CFL_VERSION     0x02050300
-#define CFL_VERSION_STR "2.5.3rc1"
+#define CFL_VERSION_STR "2.5.3"
 
 /**
  * Minimum required librdkafka version. This is checked both during
diff --git a/tools/smoketest.sh b/tools/smoketest.sh
index acfb4ac9a..af2afd6fe 100755
--- a/tools/smoketest.sh
+++ b/tools/smoketest.sh
@@ -30,7 +30,7 @@ fi
 pyvers_tested=
 
 # Run tests with python3
-for py in 3.8 ; do
+for py in 3.9 ; do
     echo "$0: # Smoketest with Python$py"
 
     if ! python$py -V ; then
diff --git a/tools/test-manylinux.sh b/tools/test-manylinux.sh
index 26ef95262..9837048ab 100755
--- a/tools/test-manylinux.sh
+++ b/tools/test-manylinux.sh
@@ -31,12 +31,16 @@ fi
 echo "$0 running from $(pwd)"
 
 function setup_ubuntu {
+    export DEBIAN_FRONTEND=noninteractive
     # Ubuntu container setup
     apt-get update
-    apt-get install -y python3.8 curl
+    apt-get install -y -q software-properties-common
+    add-apt-repository ppa:deadsnakes/ppa
     # python3-distutils is required on Ubuntu 18.04 and later but does
     # not exist on 14.04.
-    apt-get install -y python3.8-distutils || true
+    apt-get install -y -q python3.9
+    apt-get install -y -q python3.9-distutils
+    apt-get install -y -q curl
 }
 
 
@@ -61,7 +65,7 @@ function run_single_in_docker {
     # in a plethora of possibly outdated Python requirements that
     # might interfere with the newer packages from PyPi, such as six.
     # Instead install it directly from PyPa.
-    curl https://bootstrap.pypa.io/get-pip.py | python3.8
+    curl https://bootstrap.pypa.io/get-pip.py | python3.9
 
     /io/tools/smoketest.sh "$wheelhouse"
 }
@@ -78,7 +82,7 @@ function run_all_with_docker {
 
     [[ ! -z $DOCKER_IMAGES ]] || \
         # LTS and stable release of popular Linux distros.
-        DOCKER_IMAGES="ubuntu:18.04 ubuntu:20.04"
+        DOCKER_IMAGES="ubuntu:20.04 ubuntu:22.04"
 
 
     _wheels="$wheelhouse/*manylinux*.whl"