diff --git a/composer.json b/composer.json
index b8f4346444f..4ad328dbc07 100644
--- a/composer.json
+++ b/composer.json
@@ -6,7 +6,7 @@
   "homepage": "https://grpc.io",
   "license": "Apache-2.0",
   "require": {
-    "php": ">=5.5.0"
+    "php": ">=7.0.0"
   },
   "require-dev": {
     "google/auth": "^v1.3.0"
diff --git a/package.xml b/package.xml
index 84dacfad93e..fd7b4debc0d 100644
--- a/package.xml
+++ b/package.xml
@@ -1996,7 +1996,7 @@
  <dependencies>
   <required>
    <php>
-    <min>5.5.0</min>
+    <min>7.0.0</min>
    </php>
    <pearinstaller>
     <min>1.4.0</min>
diff --git a/src/php/bin/build_all_docker_images.sh b/src/php/bin/build_all_docker_images.sh
index defc5551f00..77e2df7a024 100755
--- a/src/php/bin/build_all_docker_images.sh
+++ b/src/php/bin/build_all_docker_images.sh
@@ -17,7 +17,7 @@ set -e
 cd $(dirname $0)/../../..
 
 ALL_IMAGES=( grpc-ext grpc-src alpine centos7 php-src php-future php-zts
-             fork-support i386 )
+             fork-support i386 php8 )
 
 if [[ "$1" == "--cmds" ]]; then
   for arg in "${ALL_IMAGES[@]}"
diff --git a/src/php/bin/run_all_docker_images.sh b/src/php/bin/run_all_docker_images.sh
index 7969c281dd0..a10345816d2 100755
--- a/src/php/bin/run_all_docker_images.sh
+++ b/src/php/bin/run_all_docker_images.sh
@@ -17,7 +17,7 @@ set -e
 cd $(dirname $0)/../../..
 
 ALL_IMAGES=( grpc-ext grpc-src alpine centos7 php-src php-future php-zts
-             fork-support i386 )
+             fork-support i386 php8 )
 
 if [[ "$1" == "--cmds" ]]; then
   for arg in "${ALL_IMAGES[@]}"
diff --git a/src/php/composer.json b/src/php/composer.json
index 0ba0313eade..cf9ffad83c7 100644
--- a/src/php/composer.json
+++ b/src/php/composer.json
@@ -4,7 +4,7 @@
   "license": "Apache-2.0",
   "version": "1.34.0",
   "require": {
-    "php": ">=5.5.0",
+    "php": ">=7.0.0",
     "google/protobuf": "^v3.3.0"
   },
   "require-dev": {
diff --git a/src/php/docker/alpine/Dockerfile b/src/php/docker/alpine/Dockerfile
index a71c2afeccf..67ede050773 100644
--- a/src/php/docker/alpine/Dockerfile
+++ b/src/php/docker/alpine/Dockerfile
@@ -21,8 +21,8 @@ ARG MAKEFLAGS=-j8
 
 WORKDIR /tmp
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
 
 
diff --git a/src/php/docker/centos7/Dockerfile b/src/php/docker/centos7/Dockerfile
index e6df3ef819e..9c5278e982e 100644
--- a/src/php/docker/centos7/Dockerfile
+++ b/src/php/docker/centos7/Dockerfile
@@ -35,8 +35,8 @@ ARG MAKEFLAGS=-j8
 
 WORKDIR /tmp
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
 
 
diff --git a/src/php/docker/grpc-ext/Dockerfile b/src/php/docker/grpc-ext/Dockerfile
index 93d0307c4a0..137724bd3ad 100644
--- a/src/php/docker/grpc-ext/Dockerfile
+++ b/src/php/docker/grpc-ext/Dockerfile
@@ -23,8 +23,8 @@ ARG MAKEFLAGS=-j8
 
 WORKDIR /tmp
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
 
 
diff --git a/src/php/docker/grpc-src/Dockerfile b/src/php/docker/grpc-src/Dockerfile
index 936ddc0da23..bd3acc1caf5 100644
--- a/src/php/docker/grpc-src/Dockerfile
+++ b/src/php/docker/grpc-src/Dockerfile
@@ -23,8 +23,8 @@ ARG MAKEFLAGS=-j8
 
 WORKDIR /tmp
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
 
 
diff --git a/src/php/docker/i386/Dockerfile b/src/php/docker/i386/Dockerfile
index dff43552558..58556032f91 100644
--- a/src/php/docker/i386/Dockerfile
+++ b/src/php/docker/i386/Dockerfile
@@ -23,8 +23,8 @@ ARG MAKEFLAGS=-j8
 
 WORKDIR /tmp
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
 
 
diff --git a/src/php/docker/php-future/Dockerfile b/src/php/docker/php-future/Dockerfile
index 95c0ac47a07..1817da14d3f 100644
--- a/src/php/docker/php-future/Dockerfile
+++ b/src/php/docker/php-future/Dockerfile
@@ -23,8 +23,8 @@ ARG MAKEFLAGS=-j8
 
 WORKDIR /tmp
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
 
 
diff --git a/src/php/docker/php-src/Dockerfile b/src/php/docker/php-src/Dockerfile
index 972a297aafe..f77e3dc2f7c 100644
--- a/src/php/docker/php-src/Dockerfile
+++ b/src/php/docker/php-src/Dockerfile
@@ -23,8 +23,8 @@ RUN apt-get -qq update && apt-get -qq install -y \
 
 WORKDIR /tmp
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
 
 
diff --git a/src/php/docker/php-zts/Dockerfile b/src/php/docker/php-zts/Dockerfile
index 9bc9d37152d..9889645f994 100644
--- a/src/php/docker/php-zts/Dockerfile
+++ b/src/php/docker/php-zts/Dockerfile
@@ -23,8 +23,8 @@ ARG MAKEFLAGS=-j8
 
 WORKDIR /tmp
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
 
 
diff --git a/src/php/docker/php8/Dockerfile b/src/php/docker/php8/Dockerfile
new file mode 100644
index 00000000000..47ab8f61474
--- /dev/null
+++ b/src/php/docker/php8/Dockerfile
@@ -0,0 +1,40 @@
+# Copyright 2020 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+FROM php:8.0.0RC3-cli-buster
+
+RUN apt-get -qq update && apt-get -qq install -y \
+  autoconf automake git libtool pkg-config \
+  valgrind wget zlib1g-dev
+
+ARG MAKEFLAGS=-j8
+
+
+WORKDIR /tmp
+
+# install pear
+RUN apt-get install expect -y && \
+  curl -LO http://pear.php.net/go-pear.phar && \
+  expect -c 'spawn php ./go-pear.phar; expect "or Enter to continue:"; send "\n"; expect "Currently used php.ini"; send "\n"; expect eof' && \
+  rm go-pear.phar
+
+WORKDIR /github/grpc
+
+COPY . .
+
+RUN pear package && \
+  find . -name grpc-*.tgz | xargs -I{} pecl install {}
+
+
+CMD php -d extension=grpc.so -r '$a = new \Grpc\Channel("dummy", []); echo get_class($a)."\n";'
diff --git a/src/php/tests/generated_code/AbstractGeneratedCodeTest.php b/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
index f7b47359992..a68954606f7 100644
--- a/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
+++ b/src/php/tests/generated_code/AbstractGeneratedCodeTest.php
@@ -23,7 +23,7 @@ require_once realpath(dirname(__FILE__).'/../../vendor/autoload.php');
 @include_once dirname(__FILE__).'/math.pb.php';
 @include_once dirname(__FILE__).'/math_grpc_pb.php';
 
-abstract class AbstractGeneratedCodeTest extends PHPUnit_Framework_TestCase
+abstract class AbstractGeneratedCodeTest extends \PHPUnit\Framework\TestCase
 {
     /**
      * These tests require that a server exporting the math service must be
diff --git a/src/php/tests/generated_code/GeneratedCodeTest.php b/src/php/tests/generated_code/GeneratedCodeTest.php
index 91339d390ed..f9fa573bf3e 100755
--- a/src/php/tests/generated_code/GeneratedCodeTest.php
+++ b/src/php/tests/generated_code/GeneratedCodeTest.php
@@ -20,7 +20,7 @@ require_once dirname(__FILE__).'/AbstractGeneratedCodeTest.php';
 
 class GeneratedCodeTest extends AbstractGeneratedCodeTest
 {
-    public function setUp()
+    public function setUp(): void
     {
         self::$client = new Math\MathClient(
             getenv('GRPC_TEST_HOST'), [
@@ -28,7 +28,7 @@ class GeneratedCodeTest extends AbstractGeneratedCodeTest
             ]);
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         self::$client->close();
     }
diff --git a/src/php/tests/generated_code/GeneratedCodeWithCallbackTest.php b/src/php/tests/generated_code/GeneratedCodeWithCallbackTest.php
index 60a90fa025e..fb55d1659cd 100644
--- a/src/php/tests/generated_code/GeneratedCodeWithCallbackTest.php
+++ b/src/php/tests/generated_code/GeneratedCodeWithCallbackTest.php
@@ -20,7 +20,7 @@ require_once dirname(__FILE__).'/AbstractGeneratedCodeTest.php';
 
 class GeneratedCodeWithCallbackTest extends AbstractGeneratedCodeTest
 {
-    public function setUp()
+    public function setUp(): void
     {
         self::$client = new Math\MathClient(
         getenv('GRPC_TEST_HOST'),
@@ -35,7 +35,7 @@ class GeneratedCodeWithCallbackTest extends AbstractGeneratedCodeTest
          ]);
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         self::$client->close();
     }
diff --git a/src/php/tests/unit_tests/CallCredentials2Test.php b/src/php/tests/unit_tests/CallCredentials2Test.php
index c63029f121b..35cf821645c 100644
--- a/src/php/tests/unit_tests/CallCredentials2Test.php
+++ b/src/php/tests/unit_tests/CallCredentials2Test.php
@@ -17,9 +17,9 @@
  *
  */
 
-class CallCredentials2Test extends PHPUnit_Framework_TestCase
+class CallCredentials2Test extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $credentials = Grpc\ChannelCredentials::createSsl(
             file_get_contents(dirname(__FILE__).'/../data/ca.pem'));
@@ -43,7 +43,7 @@ class CallCredentials2Test extends PHPUnit_Framework_TestCase
         );
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         unset($this->channel);
         unset($this->server);
diff --git a/src/php/tests/unit_tests/CallCredentialsTest.php b/src/php/tests/unit_tests/CallCredentialsTest.php
index 818b823da71..a88a2680dbb 100644
--- a/src/php/tests/unit_tests/CallCredentialsTest.php
+++ b/src/php/tests/unit_tests/CallCredentialsTest.php
@@ -17,9 +17,9 @@
  *
  */
 
-class CallCredentialsTest extends PHPUnit_Framework_TestCase
+class CallCredentialsTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $this->credentials = Grpc\ChannelCredentials::createSsl(
             file_get_contents(dirname(__FILE__).'/../data/ca.pem'));
@@ -49,7 +49,7 @@ class CallCredentialsTest extends PHPUnit_Framework_TestCase
         );
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         unset($this->channel);
         unset($this->server);
diff --git a/src/php/tests/unit_tests/CallInvokerTest.php b/src/php/tests/unit_tests/CallInvokerTest.php
index 00b5b998652..300d805cb04 100644
--- a/src/php/tests/unit_tests/CallInvokerTest.php
+++ b/src/php/tests/unit_tests/CallInvokerTest.php
@@ -159,16 +159,16 @@ class CallInvokerChangeRequestCall
     }
 }
 
-class CallInvokerTest extends PHPUnit_Framework_TestCase
+class CallInvokerTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $this->server = new Grpc\Server([]);
         $this->port = $this->server->addHttp2Port('0.0.0.0:0');
         $this->server->start();
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         unset($this->server);
     }
diff --git a/src/php/tests/unit_tests/CallTest.php b/src/php/tests/unit_tests/CallTest.php
index 23d8e772d0e..4d1be1b1e24 100644
--- a/src/php/tests/unit_tests/CallTest.php
+++ b/src/php/tests/unit_tests/CallTest.php
@@ -16,19 +16,19 @@
  * limitations under the License.
  *
  */
-class CallTest extends PHPUnit_Framework_TestCase
+class CallTest extends \PHPUnit\Framework\TestCase
 {
     public static $server;
     public static $port;
 
-    public static function setUpBeforeClass()
+    public static function setUpBeforeClass(): void
     {
         self::$server = new Grpc\Server([]);
         self::$port = self::$server->addHttp2Port('0.0.0.0:53000');
         self::$server->start();
     }
 
-    public function setUp()
+    public function setUp(): void
     {
         $this->channel = new Grpc\Channel('localhost:'.self::$port, [
             'force_new' => true,
@@ -38,7 +38,7 @@ class CallTest extends PHPUnit_Framework_TestCase
                                     Grpc\Timeval::infFuture());
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         $this->channel->close();
     }
diff --git a/src/php/tests/unit_tests/ChannelCredentialsTest.php b/src/php/tests/unit_tests/ChannelCredentialsTest.php
index e7e695c9c76..73963cee155 100644
--- a/src/php/tests/unit_tests/ChannelCredentialsTest.php
+++ b/src/php/tests/unit_tests/ChannelCredentialsTest.php
@@ -17,13 +17,13 @@
  *
  */
 
-class ChanellCredentialsTest extends PHPUnit_Framework_TestCase
+class ChanellCredentialsTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
     }
 
diff --git a/src/php/tests/unit_tests/ChannelTest.php b/src/php/tests/unit_tests/ChannelTest.php
index 58f96a740b6..8ae394511e8 100644
--- a/src/php/tests/unit_tests/ChannelTest.php
+++ b/src/php/tests/unit_tests/ChannelTest.php
@@ -17,13 +17,13 @@
  *
  */
 
-class ChannelTest extends PHPUnit_Framework_TestCase
+class ChannelTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         if (!empty($this->channel)) {
             $this->channel->close();
diff --git a/src/php/tests/unit_tests/EndToEndTest.php b/src/php/tests/unit_tests/EndToEndTest.php
index d0965655e0a..08b28e02b81 100644
--- a/src/php/tests/unit_tests/EndToEndTest.php
+++ b/src/php/tests/unit_tests/EndToEndTest.php
@@ -16,9 +16,9 @@
  * limitations under the License.
  *
  */
-class EndToEndTest extends PHPUnit_Framework_TestCase
+class EndToEndTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $this->server = new Grpc\Server([]);
         $this->port = $this->server->addHttp2Port('0.0.0.0:0');
@@ -28,7 +28,7 @@ class EndToEndTest extends PHPUnit_Framework_TestCase
         $this->server->start();
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         $this->channel->close();
         unset($this->server);
diff --git a/src/php/tests/unit_tests/InterceptorTest.php b/src/php/tests/unit_tests/InterceptorTest.php
index acd68fc45a2..5e87679a3a2 100644
--- a/src/php/tests/unit_tests/InterceptorTest.php
+++ b/src/php/tests/unit_tests/InterceptorTest.php
@@ -215,9 +215,9 @@ class StopCallInterceptor extends Grpc\Interceptor
     }
 }
 
-class InterceptorTest extends PHPUnit_Framework_TestCase
+class InterceptorTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $this->server = new Grpc\Server([]);
         $this->port = $this->server->addHttp2Port('0.0.0.0:0');
@@ -227,7 +227,7 @@ class InterceptorTest extends PHPUnit_Framework_TestCase
         $this->server->start();
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         $this->channel->close();
         unset($this->server);
diff --git a/src/php/tests/unit_tests/PersistentChannelTests/PersistentChannelTest.php b/src/php/tests/unit_tests/PersistentChannelTests/PersistentChannelTest.php
index 7b44221f89b..f10daeb93fb 100644
--- a/src/php/tests/unit_tests/PersistentChannelTests/PersistentChannelTest.php
+++ b/src/php/tests/unit_tests/PersistentChannelTests/PersistentChannelTest.php
@@ -20,13 +20,13 @@
 /**
  * @group persistent_list_bound_tests
  */
-class PersistentListTest extends PHPUnit_Framework_TestCase
+class PersistentListTest extends \PHPUnit\Framework\TestCase
 {
-  public function setUp()
+  public function setUp(): void
   {
   }
 
-  public function tearDown()
+  public function tearDown(): void
   {
     $channel_clean_persistent =
         new Grpc\Channel('localhost:50010', []);
diff --git a/src/php/tests/unit_tests/SecureEndToEndTest.php b/src/php/tests/unit_tests/SecureEndToEndTest.php
index 071598c4c19..da9d9d07fac 100644
--- a/src/php/tests/unit_tests/SecureEndToEndTest.php
+++ b/src/php/tests/unit_tests/SecureEndToEndTest.php
@@ -16,9 +16,9 @@
  * limitations under the License.
  *
  */
-class SecureEndToEndTest extends PHPUnit_Framework_TestCase
+class SecureEndToEndTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $credentials = Grpc\ChannelCredentials::createSsl(
             file_get_contents(dirname(__FILE__).'/../data/ca.pem'));
@@ -42,7 +42,7 @@ class SecureEndToEndTest extends PHPUnit_Framework_TestCase
         );
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         $this->channel->close();
         unset($this->server);
diff --git a/src/php/tests/unit_tests/ServerTest.php b/src/php/tests/unit_tests/ServerTest.php
index cab92e59419..b29a6b0eac3 100644
--- a/src/php/tests/unit_tests/ServerTest.php
+++ b/src/php/tests/unit_tests/ServerTest.php
@@ -17,14 +17,14 @@
  *
  */
 
-class ServerTest extends PHPUnit_Framework_TestCase
+class ServerTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
         $this->server = null;
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         unset($this->server);
     }
diff --git a/src/php/tests/unit_tests/TimevalTest.php b/src/php/tests/unit_tests/TimevalTest.php
index 000b2db32d5..1a525088b2d 100644
--- a/src/php/tests/unit_tests/TimevalTest.php
+++ b/src/php/tests/unit_tests/TimevalTest.php
@@ -16,13 +16,13 @@
  * limitations under the License.
  *
  */
-class TimevalTest extends PHPUnit_Framework_TestCase
+class TimevalTest extends \PHPUnit\Framework\TestCase
 {
-    public function setUp()
+    public function setUp(): void
     {
     }
 
-    public function tearDown()
+    public function tearDown(): void
     {
         unset($this->time);
     }
diff --git a/templates/composer.json.template b/templates/composer.json.template
index a9cc6cca865..e778ab08d76 100644
--- a/templates/composer.json.template
+++ b/templates/composer.json.template
@@ -8,7 +8,7 @@
     "homepage": "https://grpc.io",
     "license": "Apache-2.0",
     "require": {
-      "php": ">=5.5.0"
+      "php": ">=7.0.0"
     },
     "require-dev": {
       "google/auth": "^v1.3.0"
diff --git a/templates/package.xml.template b/templates/package.xml.template
index 3273c7987ef..de65792d4ef 100644
--- a/templates/package.xml.template
+++ b/templates/package.xml.template
@@ -52,7 +52,7 @@
    <dependencies>
     <required>
      <php>
-      <min>5.5.0</min>
+      <min>7.0.0</min>
      </php>
      <pearinstaller>
       <min>1.4.0</min>
diff --git a/templates/src/php/composer.json.template b/templates/src/php/composer.json.template
index 9a1c5789040..e1c36461a88 100644
--- a/templates/src/php/composer.json.template
+++ b/templates/src/php/composer.json.template
@@ -6,7 +6,7 @@
     "license": "Apache-2.0",
     "version": "${settings.php_version.php_composer()}",
     "require": {
-      "php": ">=5.5.0",
+      "php": ">=7.0.0",
       "google/protobuf": "^v3.3.0"
     },
     "require-dev": {
diff --git a/templates/src/php/docker/download_phpunit.include b/templates/src/php/docker/download_phpunit.include
index 5387119bf55..8d5e17f0ab4 100644
--- a/templates/src/php/docker/download_phpunit.include
+++ b/templates/src/php/docker/download_phpunit.include
@@ -1,3 +1,3 @@
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && ${'\\'}
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && ${'\\'}
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && ${'\\'}
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && ${'\\'}
   chmod +x /usr/local/bin/phpunit
diff --git a/templates/src/php/docker/php8/Dockerfile.template b/templates/src/php/docker/php8/Dockerfile.template
new file mode 100644
index 00000000000..eb00edb073e
--- /dev/null
+++ b/templates/src/php/docker/php8/Dockerfile.template
@@ -0,0 +1,36 @@
+%YAML 1.2
+--- |
+  # Copyright 2020 gRPC authors.
+  #
+  # Licensed under the Apache License, Version 2.0 (the "License");
+  # you may not use this file except in compliance with the License.
+  # You may obtain a copy of the License at
+  #
+  #     http://www.apache.org/licenses/LICENSE-2.0
+  #
+  # Unless required by applicable law or agreed to in writing, software
+  # distributed under the License is distributed on an "AS IS" BASIS,
+  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  # See the License for the specific language governing permissions and
+  # limitations under the License.
+
+  FROM php:8.0.0RC3-cli-buster
+
+  RUN apt-get -qq update && apt-get -qq install -y ${'\\'}
+    autoconf automake git libtool pkg-config ${'\\'}
+    valgrind wget zlib1g-dev
+
+  ARG MAKEFLAGS=-j8
+
+
+  WORKDIR /tmp
+
+  # install pear
+  RUN apt-get install expect -y && ${'\\'}
+    curl -LO http://pear.php.net/go-pear.phar && ${'\\'}
+    expect -c 'spawn php ./go-pear.phar; expect "or Enter to continue:"; send "\n"; expect "Currently used php.ini"; send "\n"; expect eof' && ${'\\'}
+    rm go-pear.phar
+
+  <%include file="../pecl_ext_build_src.include" />
+
+  CMD php -d extension=grpc.so -r '$a = new \Grpc\Channel("dummy", []); echo get_class($a)."\n";'
diff --git a/tools/dockerfile/distribtest/php7_stretch_x64/Dockerfile b/tools/dockerfile/distribtest/php7_stretch_x64/Dockerfile
index ec74b00a75e..7f013b7386e 100644
--- a/tools/dockerfile/distribtest/php7_stretch_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/php7_stretch_x64/Dockerfile
@@ -16,6 +16,6 @@ FROM debian:stretch
 
 RUN apt-get update && apt-get install -y php php-dev php-pear wget zlib1g-dev
 
-RUN wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-  mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+RUN wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+  mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
   chmod +x /usr/local/bin/phpunit
diff --git a/tools/gce/linux_kokoro_performance_worker_init.sh b/tools/gce/linux_kokoro_performance_worker_init.sh
index a325611ceae..e81ba212342 100755
--- a/tools/gce/linux_kokoro_performance_worker_init.sh
+++ b/tools/gce/linux_kokoro_performance_worker_init.sh
@@ -162,8 +162,8 @@ gem install bundler
 
 # PHP dependencies
 sudo apt-get install -y php7.2 php7.2-dev php-pear unzip zlib1g-dev
-sudo wget https://phar.phpunit.de/phpunit-5.7.27.phar && \
-    sudo mv phpunit-5.7.27.phar /usr/local/bin/phpunit && \
+sudo wget https://phar.phpunit.de/phpunit-8.5.8.phar && \
+    sudo mv phpunit-8.5.8.phar /usr/local/bin/phpunit && \
     sudo chmod +x /usr/local/bin/phpunit
 curl -sS https://getcomposer.org/installer | php
 sudo mv composer.phar /usr/local/bin/composer