diff --git a/ci/centos-stream-8/Dockerfile b/ci/centos-stream-8/Dockerfile
index 32a0cc56fa..e2f31e8846 100644
--- a/ci/centos-stream-8/Dockerfile
+++ b/ci/centos-stream-8/Dockerfile
@@ -13,12 +13,14 @@ RUN dnf -y install \
     cmake \
     diffutils \
     flex \
-    git \
     gcc \
     gcc-c++ \
+    git \
     libpcap-devel \
     make \
+    openssl \
     openssl-devel \
+    python3 \
     python3-devel \
     python3-pip\
     sqlite \
diff --git a/ci/centos-stream-9/Dockerfile b/ci/centos-stream-9/Dockerfile
index b2ac5783fb..57e23f54cc 100644
--- a/ci/centos-stream-9/Dockerfile
+++ b/ci/centos-stream-9/Dockerfile
@@ -24,12 +24,14 @@ RUN dnf -y --nobest install \
     cmake \
     diffutils \
     flex \
-    git \
     gcc \
     gcc-c++ \
+    git \
     libpcap-devel \
     make \
+    openssl \
     openssl-devel \
+    python3 \
     python3-devel \
     python3-pip\
     sqlite \
diff --git a/ci/debian-10/Dockerfile b/ci/debian-10/Dockerfile
index 3d554e8a43..c655f6f031 100644
--- a/ci/debian-10/Dockerfile
+++ b/ci/debian-10/Dockerfile
@@ -31,6 +31,7 @@ RUN apt-get update && apt-get -y install \
     wget \
     xz-utils \
     ccache \
+  && apt autoclean \
   && rm -rf /var/lib/apt/lists/*
 
 # Install a recent CMake to build Spicy.
diff --git a/ci/debian-11/Dockerfile b/ci/debian-11/Dockerfile
index a62cc35865..15f66e8e2c 100644
--- a/ci/debian-11/Dockerfile
+++ b/ci/debian-11/Dockerfile
@@ -28,6 +28,7 @@ RUN apt-get update && apt-get -y install \
     curl \
     wget \
     xz-utils \
+  && apt autoclean \
   && rm -rf /var/lib/apt/lists/*
 
 RUN pip3 install websockets junit2html
diff --git a/ci/debian-9-32bit/Dockerfile b/ci/debian-9-32bit/Dockerfile
index 3466c1c751..7b0a177e14 100644
--- a/ci/debian-9-32bit/Dockerfile
+++ b/ci/debian-9-32bit/Dockerfile
@@ -32,6 +32,7 @@ RUN apt-get update && apt-get -y install \
     curl \
     wget \
     xz-utils \
+  && apt autoclean \
   && rm -rf /var/lib/apt/lists/*
 
 # Recent CMake.
diff --git a/ci/debian-9/Dockerfile b/ci/debian-9/Dockerfile
index 6584dfb08e..b4aa291e9b 100644
--- a/ci/debian-9/Dockerfile
+++ b/ci/debian-9/Dockerfile
@@ -32,13 +32,14 @@ RUN apt-get update && apt-get -y install \
     curl \
     wget \
     xz-utils \
+  && apt autoclean \
   && rm -rf /var/lib/apt/lists/*
 
 # Recent CMake.
 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
 
-# junit2html >= 31.0.0 requires jinj2 >= 3.0 which requires python >= 3.7 which is
+# junit2html >= 31.0.0 requires jinja2 >= 3.0 which requires python >= 3.7 which is
 # a higher version of python3 than debian 9 provides. Fix the version of junit2html
 # to the last version before they required the newer jinja2.
 RUN pip3 install websockets junit2html==30.0.6
diff --git a/ci/fedora-34/Dockerfile b/ci/fedora-34/Dockerfile
index 1431fcf723..616c121092 100644
--- a/ci/fedora-34/Dockerfile
+++ b/ci/fedora-34/Dockerfile
@@ -11,12 +11,14 @@ RUN dnf -y install \
     diffutils \
     findutils \
     flex \
-    git \
     gcc \
     gcc-c++ \
+    git \
     libpcap-devel \
     make \
+    openssl \
     openssl-devel \
+    python3 \
     python3-devel \
     python3-pip\
     sqlite \
diff --git a/ci/fedora-35/Dockerfile b/ci/fedora-35/Dockerfile
index 708ed8321a..202d002aab 100644
--- a/ci/fedora-35/Dockerfile
+++ b/ci/fedora-35/Dockerfile
@@ -11,12 +11,14 @@ RUN dnf -y install \
     diffutils \
     findutils \
     flex \
-    git \
     gcc \
     gcc-c++ \
+    git \
     libpcap-devel \
     make \
+    openssl \
     openssl-devel \
+    python3 \
     python3-devel \
     python3-pip\
     sqlite \
diff --git a/ci/ubuntu-18.04/Dockerfile b/ci/ubuntu-18.04/Dockerfile
index 3f18608920..8aefc632d6 100644
--- a/ci/ubuntu-18.04/Dockerfile
+++ b/ci/ubuntu-18.04/Dockerfile
@@ -34,6 +34,7 @@ RUN apt-get update && apt-get -y install \
     bc \
     lcov \
     ccache \
+  && apt-get autoclean \
   && rm -rf /var/lib/apt/lists/*
 
 # Recent CMake.
diff --git a/ci/ubuntu-20.04/Dockerfile b/ci/ubuntu-20.04/Dockerfile
index cc9c0fcddf..7619c8c093 100644
--- a/ci/ubuntu-20.04/Dockerfile
+++ b/ci/ubuntu-20.04/Dockerfile
@@ -32,6 +32,7 @@ RUN apt-get update && apt-get -y install \
     ruby \
     bc \
     lcov \
+  && apt autoclean \
   && rm -rf /var/lib/apt/lists/*
 
 RUN pip3 install websockets junit2html
diff --git a/ci/ubuntu-21.10/Dockerfile b/ci/ubuntu-21.10/Dockerfile
index 47aea5c4aa..b106ccd9f4 100644
--- a/ci/ubuntu-21.10/Dockerfile
+++ b/ci/ubuntu-21.10/Dockerfile
@@ -32,6 +32,7 @@ RUN apt-get update && apt-get -y install \
     ruby \
     bc \
     lcov \
+  && apt autoclean \
   && rm -rf /var/lib/apt/lists/*
 
 RUN pip3 install websockets junit2html