diff --git a/t/api-rest/Dockerfile b/t/api-rest/Dockerfile
index edcd09e100..7e22809b13 100644
--- a/t/api-rest/Dockerfile
+++ b/t/api-rest/Dockerfile
@@ -1,11 +1,11 @@
-# DOCKER_NAME=ngcp-panel-tests-rest-api-buster
-FROM docker.mgm.sipwise.com/sipwise-buster:latest
+# DOCKER_NAME=ngcp-panel-tests-rest-api-bullseye
+FROM docker.mgm.sipwise.com/sipwise-bullseye:latest
 
 # Important! Update this no-op ENV variable when this Dockerfile
 # is updated with the current date. It will force refresh of all
 # of the base images and things like `apt-get update` won't be using
 # old cached versions when the Dockerfile is built.
-ENV REFRESHED_AT 2019-06-27
+ENV REFRESHED_AT 2021-05-03
 
 # files that get-code generates
 COPY t/api-rest/sources.list.d/builddeps.list /etc/apt/sources.list.d/
@@ -56,15 +56,15 @@ WORKDIR /home/testuser
 #
 # you need to put the proper NGCP sources at t/sources.list.d/builddeps.list
 # for instance, trunk:
-# echo "deb https://deb.sipwise.com/autobuild/ release-trunk-buster main" > t/sources.list.d/builddeps.list
+# echo "deb https://deb.sipwise.com/autobuild/ release-trunk-bullseye main" > t/sources.list.d/builddeps.list
 #
 # NOTE: run the following command from root folder of git repository:
-# % docker build --tag="ngcp-panel-tests-rest-api-buster" -f t/api-rest/Dockerfile .
-# % docker run --rm -i -t -v $(pwd):/code:rw ngcp-panel-tests-rest-api-buster:latest bash
+# % docker build --tag="ngcp-panel-tests-rest-api-bullseye" -f t/api-rest/Dockerfile .
+# % docker run --rm -i -t -v $(pwd):/code:rw ngcp-panel-tests-rest-api-bullseye:latest bash
 #
 # Use the existing docker image (run from ngcp-panel base directory):
-# % docker pull docker.mgm.sipwise.com/ngcp-panel-tests-rest-api-buster
-# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/ngcp-panel-tests-rest-api-buster:latest bash
+# % docker pull docker.mgm.sipwise.com/ngcp-panel-tests-rest-api-bullseye
+# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/ngcp-panel-tests-rest-api-bullseye:latest bash
 #
 # Inside docker:
 #   su - testuser
diff --git a/t/api-rest2/Dockerfile b/t/api-rest2/Dockerfile
index cb38d154c5..39dd67292f 100644
--- a/t/api-rest2/Dockerfile
+++ b/t/api-rest2/Dockerfile
@@ -1,11 +1,11 @@
-# DOCKER_NAME=ngcp-panel-tests-rest-api2-buster
-FROM docker.mgm.sipwise.com/sipwise-buster:latest
+# DOCKER_NAME=ngcp-panel-tests-rest-api2-bullseye
+FROM docker.mgm.sipwise.com/sipwise-bullseye:latest
 
 # Important! Update this no-op ENV variable when this Dockerfile
 # is updated with the current date. It will force refresh of all
 # of the base images and things like `apt-get update` won't be using
 # old cached versions when the Dockerfile is built.
-ENV REFRESHED_AT 2019-07-26
+ENV REFRESHED_AT 2021-05-03
 
 # files that get-code generates
 COPY t/api-rest/sources.list.d/builddeps.list /etc/apt/sources.list.d/
@@ -35,15 +35,15 @@ WORKDIR /code/
 # jump to the next section if you don't want to build yourself!:
 #
 # you need to put the proper NGCP sources at t/api-rest2/sources.list.d/builddeps.list for instance, trunk:
-# % echo "deb https://deb.sipwise.com/autobuild/ release-trunk-buster main" > t/api-rest2/sources.list.d/builddeps.list
+# % echo "deb https://deb.sipwise.com/autobuild/ release-trunk-bullseye main" > t/api-rest2/sources.list.d/builddeps.list
 #
 # NOTE: run the following command (from root folder of git repository):
-# % docker build --tag="ngcp-panel-tests-rest-api2-buster" -f t/api-rest2/Dockerfile .
-# % docker run --rm -i -t -v $(pwd):/code:ro -v $(pwd):/results:rw ngcp-panel-tests-rest-api2-buster:latest bash
+# % docker build --tag="ngcp-panel-tests-rest-api2-bullseye" -f t/api-rest2/Dockerfile .
+# % docker run --rm -i -t -v $(pwd):/code:ro -v $(pwd):/results:rw ngcp-panel-tests-rest-api2-bullseye:latest bash
 #
 # Use the existing docker image (run from ngcp-panel base directory):
-# % docker pull docker.mgm.sipwise.com/ngcp-panel-tests-rest-api2-buster
-# % docker run --rm -i -t -v $(pwd):/code:ro -v $(pwd):/results:rw docker.mgm.sipwise.com/ngcp-panel-tests-rest-api2-buster:latest bash
+# % docker pull docker.mgm.sipwise.com/ngcp-panel-tests-rest-api2-bullseye
+# % docker run --rm -i -t -v $(pwd):/code:ro -v $(pwd):/results:rw docker.mgm.sipwise.com/ngcp-panel-tests-rest-api2-bullseye:latest bash
 #
 # Inside docker. To run the full REST-API-2 test suite:
 #   ./t/api-rest2/testrunner $IP_OF_NGCP_SYSTEM # IP_OF_NGCP_SYSTEM can be e.g. IP of a `vagrant up ce-trunk` system (eth1)
diff --git a/t/selenium/Dockerfile b/t/selenium/Dockerfile
index bfa0ff7ece..dcee482db3 100644
--- a/t/selenium/Dockerfile
+++ b/t/selenium/Dockerfile
@@ -1,11 +1,11 @@
-# DOCKER_NAME=ngcp-panel-tests-selenium-buster
-FROM docker.mgm.sipwise.com/sipwise-buster:latest
+# DOCKER_NAME=ngcp-panel-tests-selenium-bullseye
+FROM docker.mgm.sipwise.com/sipwise-bullseye:latest
 
 # Important! Update this no-op ENV variable when this Dockerfile
 # is updated with the current date. It will force refresh of all
 # of the base images and things like `apt-get update` won't be using
 # old cached versions when the Dockerfile is built.
-ENV REFRESHED_AT 2019-07-30
+ENV REFRESHED_AT 2021-05-03
 
 RUN apt-get update
 RUN apt-get install --assume-yes \
@@ -74,12 +74,12 @@ COPY t/selenium/jenkins_docker_run /home/selenium/
 # ----------------------
 # When you want to build the base image from scratch (jump to the next section if you don't want to build yourself!):
 # NOTE: run the following command from root folder of git repository:
-# % docker build --tag="ngcp-panel-tests-selenium-buster" -f t/selenium/Dockerfile .
-# % docker run --rm -p 5999:5999 --shm-size 4g -i -t -v $(pwd):/code:rw ngcp-panel-tests-selenium-buster:latest bash
+# % docker build --tag="ngcp-panel-tests-selenium-bullseye" -f t/selenium/Dockerfile .
+# % docker run --rm -p 5999:5999 --shm-size 4g -i -t -v $(pwd):/code:rw ngcp-panel-tests-selenium-bullseye:latest bash
 #
 # Use the existing docker image:
-# % docker pull docker.mgm.sipwise.com/ngcp-panel-tests-selenium-buster
-# % docker run --rm -p 5999:5999 --shm-size 4g -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/ngcp-panel-tests-selenium-buster:latest bash
+# % docker pull docker.mgm.sipwise.com/ngcp-panel-tests-selenium-bullseye
+# % docker run --rm -p 5999:5999 --shm-size 4g -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/ngcp-panel-tests-selenium-bullseye:latest bash
 #
 # Inside docker:
 #   su - selenium