diff --git a/.cirrus.yml b/.cirrus.yml
index d89c32f8..249dfe00 100644
--- a/.cirrus.yml
+++ b/.cirrus.yml
@@ -95,14 +95,6 @@ centosstream8_task:
   << : *CI_TEMPLATE
   << : *UNIX_ENV
 
-centos7_task:
-  container:
-    # CentOS 7 EOL: June 30, 2024
-    dockerfile: ci/centos-7/Dockerfile
-    << : *RESOURCES_TEMPLATE
-  << : *CI_TEMPLATE
-  << : *UNIX_ENV
-
 debian12_task:
   container:
     # Debian 12 (bookworm) EOL: TBD
@@ -119,14 +111,6 @@ debian11_task:
   << : *CI_TEMPLATE
   << : *UNIX_ENV
 
-debian10_task:
-  container:
-    # Debian 10 EOL: June 2024
-    dockerfile: ci/debian-10/Dockerfile
-    << : *RESOURCES_TEMPLATE
-  << : *CI_TEMPLATE
-  << : *UNIX_ENV
-
 opensuse_leap_15_5_task:
   container:
     # Opensuse Leap 15.5 EOL: ~Dec 2024
diff --git a/ci/centos-7/Dockerfile b/ci/centos-7/Dockerfile
deleted file mode 100644
index b6317c5d..00000000
--- a/ci/centos-7/Dockerfile
+++ /dev/null
@@ -1,49 +0,0 @@
-FROM centos:7
-
-# A version field to invalidate Cirrus's build cache when needed, as suggested in
-# https://github.com/cirruslabs/cirrus-ci-docs/issues/544#issuecomment-566066822
-ENV DOCKERFILE_VERSION 20220519
-
-# Disabled lookup of fastest mirror since the list seems to be outdated and no valid mirror can be detected.
-RUN sed -i 's/enabled=1/enabled=0/' /etc/yum/pluginconf.d/fastestmirror.conf
-
-# The version of git in the standard repos is 1.8 and CI needs 2.3+
-# for the use of GIT_SSH_COMMAND when cloning private repos.
-RUN yum -y install \
-    https://repo.ius.io/ius-release-el7.rpm \
-    https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm \
-  && yum -y install git236 ccache \
-  && yum clean all && rm -rf /var/cache/yum
-
-RUN yum -y install \
-    epel-release \
-  && yum clean all && rm -rf /var/cache/yum
-
-RUN yum -y install \
-    centos-release-scl \
-  && yum clean all && rm -rf /var/cache/yum
-
-RUN yum -y install \
-    devtoolset-8 \
-  && yum clean all && rm -rf /var/cache/yum
-
-RUN yum -y install \
-    cmake3 \
-    diffutils \
-    make \
-    openssl \
-    openssl-devel \
-    rh-python38 \
-    rh-python38-devel \
-    rh-python38-python-devel \
-    rh-python38-pip \
-  && yum clean all && rm -rf /var/cache/yum
-
-RUN echo 'unset BASH_ENV PROMPT_COMMAND ENV' > /usr/bin/zeek-ci-env && \
-    echo 'source /opt/rh/devtoolset-8/enable' >> /usr/bin/zeek-ci-env && \
-    echo 'source /opt/rh/rh-python38/enable' >> /usr/bin/zeek-ci-env && \
-    echo 'export PATH=${PATH}:${FLEX_DIR}/bin' >> /usr/bin/zeek-ci-env
-
-ENV BASH_ENV="/usr/bin/zeek-ci-env" \
-    ENV="/usr/bin/zeek-ci-env" \
-    PROMPT_COMMAND=". /usr/bin/zeek-ci-env"
diff --git a/ci/debian-10/Dockerfile b/ci/debian-10/Dockerfile
deleted file mode 100644
index f0907084..00000000
--- a/ci/debian-10/Dockerfile
+++ /dev/null
@@ -1,27 +0,0 @@
-FROM debian:10
-
-ENV DEBIAN_FRONTEND="noninteractive" TZ="America/Los_Angeles"
-
-# A version field to invalidate Cirrus's build cache when needed, as suggested in
-# https://github.com/cirruslabs/cirrus-ci-docs/issues/544#issuecomment-566066822
-ENV DOCKERFILE_VERSION 20230813
-
-ENV CMAKE_DIR "/opt/cmake"
-ENV CMAKE_VERSION "3.19.1"
-ENV PATH "${CMAKE_DIR}/bin:${PATH}"
-
-RUN apt-get update && apt-get -y install \
-    curl \
-    g++ \
-    gcc \
-    git \
-    libssl-dev \
-    make \
-    python3 \
-    python3-dev \
-  && apt autoclean \
-  && rm -rf /var/lib/apt/lists/*
-
-# Install a recent CMake to build Spicy.
-RUN mkdir -p "${CMAKE_DIR}" \
-  && curl -sSL "https://github.com/Kitware/CMake/releases/download/v${CMAKE_VERSION}/cmake-${CMAKE_VERSION}-Linux-x86_64.tar.gz" | tar xzf - -C "${CMAKE_DIR}" --strip-components 1