php8.1 testing
diff --git a/kokoro/linux/dockerfile/test/php80/Dockerfile b/kokoro/linux/dockerfile/test/php80/Dockerfile
index 8093eae..5b382d0 100644
--- a/kokoro/linux/dockerfile/test/php80/Dockerfile
+++ b/kokoro/linux/dockerfile/test/php80/Dockerfile
@@ -1,4 +1,4 @@
-FROM debian:jessie
+FROM debian:stretch
 
 # Install dependencies.  We start with the basic ones require to build protoc
 # and the C++ build
@@ -29,7 +29,7 @@
 
 # Install php dependencies
 RUN apt-get clean && apt-get update && apt-get install -y --force-yes \
-  php5 \
+  php \
   libcurl4-openssl-dev \
   libgmp-dev \
   libgmp3-dev \
@@ -90,6 +90,34 @@
   && cp phpunit /usr/local/php-8.0/bin \
   && mv phpunit /usr/local/php-8.0-zts/bin
 
+# php 8.1
+RUN cd php-src \
+  && git checkout php-8.1.2 \
+  && ./buildconf --force
+RUN cd php-src \
+  && ./configure \
+  --enable-bcmath \
+  --enable-mbstring \
+  --with-gmp \
+  --with-openssl \
+  --with-zlib \
+  --prefix=/usr/local/php-8.1 \
+  && make \
+  && make install \
+  && make clean
+RUN cd php-src \
+  && ./configure \
+  --enable-bcmath \
+  --enable-mbstring \
+  --enable-maintainer-zts \
+  --with-gmp \
+  --with-openssl \
+  --with-zlib \
+  --prefix=/usr/local/php-8.1-zts \
+  && make \
+  && make install \
+  && make clean
+
 # Install php dependencies
 RUN apt-get clean && apt-get update && apt-get install -y --force-yes \
   valgrind \
diff --git a/tests.sh b/tests.sh
index 290f110..13bf034 100755
--- a/tests.sh
+++ b/tests.sh
@@ -496,6 +496,8 @@
   use_php $1
   pushd php
   rm -rf vendor
+  php -v
+  php -m
   composer update
   composer test
   popd
@@ -505,6 +507,8 @@
 test_php_c() {
   pushd php
   rm -rf vendor
+  php -v
+  php -m
   composer update
   composer test_c
   popd
@@ -572,7 +576,9 @@
 
 build_php8.0_all() {
   build_php 8.0
+  build_php 8.1
   build_php_c 8.0
+  build_php_c 8.1
 }
 
 build_php_all_32() {