diff --git a/t/Dockerfile b/t/Dockerfile
index cb93a8be..966c387f 100644
--- a/t/Dockerfile
+++ b/t/Dockerfile
@@ -1,11 +1,11 @@
-# DOCKER_NAME=kamailio-config-tests-bookworm
-FROM docker.mgm.sipwise.com/sipwise-bookworm:latest
+# DOCKER_NAME=kamailio-config-tests-trixie
+FROM docker.mgm.sipwise.com/sipwise-trixie: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 2023-06-26
+ENV REFRESHED_AT 2025-12-30
 
 RUN apt-get update && apt-get install --assume-yes python3-yaml python3-junitxml \
   make libtemplate-perl libyaml-perl python3-pytest parallel \
@@ -21,12 +21,12 @@ WORKDIR /code/
 # When you want to build the base image from scratch
 # (jump to the next section if you don't want to build yourself!):
 #
-# % docker build --tag="kamailio-config-tests-bookworm" -f t//Dockerfile .
-# % docker run --rm -i -t -v $(pwd):/code:rw kamailio-config-tests-bookworm:latest bash
+# % docker build --tag="kamailio-config-tests-trixie" -f t//Dockerfile .
+# % docker run --rm -i -t -v $(pwd):/code:rw kamailio-config-tests-trixie:latest bash
 #
 # Use the existing docker image:
-# % docker pull docker.mgm.sipwise.com/kamailio-config-tests-bookworm
-# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/kamailio-config-tests-bookworm:latest bash
+# % docker pull docker.mgm.sipwise.com/kamailio-config-tests-trixie
+# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/kamailio-config-tests-trixie:latest bash
 #
 # Inside docker (the command is in history, just press UP button):
 #   ./t/testrunner
diff --git a/t/external/Dockerfile b/t/external/Dockerfile
deleted file mode 100644
index 484e8679..00000000
--- a/t/external/Dockerfile
+++ /dev/null
@@ -1,33 +0,0 @@
-# DOCKER_NAME=k-c-t-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 2023-03-07
-ENV BASE_DIR=/code
-
-RUN apt-get update && apt-get install --assume-yes \
-    parallel python3-yaml sip-tester tcpdump \
-    libconfig-tiny-perl libdata-dump-perl libjson-perl \
-    liblist-moreutils-perl libtemplate-perl libtext-csv-perl \
-    libtext-diff-perl libtry-tiny-perl libyaml-libyaml-perl \
-    libfile-slurp-perl libhash-merge-perl libwww-perl \
-    && rm -rf /var/lib/apt/lists/*
-
-WORKDIR /code/
-################################################################################
-# Instructions for usage
-# ----------------------
-# When you want to build the base image from scratch
-# (jump to the next section if you don't want to build yourself!):
-#
-# % docker build --tag="k-c-t-bullseye" -f t/external/Dockerfile .
-# % docker run --rm -i -t -v $(pwd):/code:rw k-c-t-bullseye:latest bash
-#
-# Use the existing docker image:
-# % docker pull docker.mgm.sipwise.com/k-c-t-bullseye
-# % docker run --rm -i -t -v $(pwd):/code:rw docker.mgm.sipwise.com/k-c-t-bullseye:latest bash
-#
-################################################################################