diff --git a/Dockerfile b/Dockerfile
index e404320ef8..9e85457301 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,6 +1,6 @@
 # When rebasing to new Fedora, also update openshift/release:
 # https://github.com/openshift/release/tree/master/ci-operator/config/coreos/coreos-assembler/coreos-coreos-assembler-main.yaml
-FROM quay.io/fedora/fedora:39
+FROM quay.io/fedora/fedora:40
 WORKDIR /root/containerbuild
 
 # Keep this Dockerfile idempotent for local development rebuild use cases.
diff --git a/build.sh b/build.sh
index ffe9ee79d7..6f13a326ab 100755
--- a/build.sh
+++ b/build.sh
@@ -45,7 +45,7 @@ install_rpms() {
     frozendeps=""
 
     # We freeze the version for now since we're carrying patches.
-    frozendeps+=" $(echo osbuild{,-ostree,-selinux,-tools}-114-1.fc39.noarch)"
+    frozendeps+=" $(echo osbuild{,-ostree,-selinux,-tools}-114-1.fc40.noarch)"
 
     # First, a general update; this is best practice.  We also hit an issue recently
     # where qemu implicitly depended on an updated libusbx but didn't have a versioned
diff --git a/src/cmdlib.sh b/src/cmdlib.sh
index 48a678baca..37041a27b4 100755
--- a/src/cmdlib.sh
+++ b/src/cmdlib.sh
@@ -733,6 +733,9 @@ runvm() {
     # and include all GPG keys
     find /etc/pki/rpm-gpg/ -type f >> "${vmpreparedir}/hostfiles"
 
+    local cmdoutput
+    cmdoutput=${tmp_builddir}/cmd-output.txt
+
     # the reason we do a heredoc here is so that the var substition takes
     # place immediately instead of having to proxy them through to the VM
     cat > "${vmpreparedir}/init" <<EOF
@@ -752,7 +755,7 @@ rc=0
 # - Use a subshell because otherwise init will use workdir as its cwd and we won't
 #   be able to unmount the virtiofs mount cleanly. This leads to consistency issues.
 if [ -z "${RUNVM_SHELL:-}" ]; then
-  (cd ${workdir}; bash ${tmp_builddir}/cmd.sh |& tee /dev/virtio-ports/cosa-cmdout) || rc=\$?
+  (cd ${workdir}; bash ${tmp_builddir}/cmd.sh |& tee ${cmdoutput}) || rc=\$?
 else
   (cd ${workdir}; bash)
 fi
@@ -786,7 +789,9 @@ EOF
         printf '%q ' "$arg" >> "${tmp_builddir}"/cmd.sh
     done
 
-    touch "${runvm_console}"
+    touch "${runvm_console}" "${cmdoutput}"
+    setpriv --pdeathsig SIGTERM -- tail -qF "${cmdoutput}" --pid $$ &
+    local tail_pid=$!
 
     # There seems to be some false positives in shellcheck
     # https://github.com/koalaman/shellcheck/issues/2217
@@ -821,9 +826,7 @@ EOF
 
     if [ -z "${RUNVM_SHELL:-}" ]; then
         if ! "${kola_args[@]}" -- "${base_qemu_args[@]}" \
-            -device virtserialport,chardev=virtioserial0,name=cosa-cmdout \
-            -chardev stdio,id=virtioserial0 \
-            "${qemu_args[@]}" <&-; then # the <&- here closes stdin otherwise qemu waits forever
+            "${qemu_args[@]}"; then
                 cat "${runvm_console}"
                 fatal "Failed to run 'kola qemuexec'"
         fi
@@ -842,6 +845,9 @@ EOF
     fi
     rc="$(cat "${rc_file}")"
 
+    # cleanup tail before nuking dir containing file it's following
+    kill "$tail_pid"
+
     if [ -n "${cleanup_tmpdir:-}" ]; then
         rm -rf "${tmp_builddir}"
         unset tmp_builddir
diff --git a/tests/containers/tang/Containerfile b/tests/containers/tang/Containerfile
index a0d91a2243..f36fe9132c 100644
--- a/tests/containers/tang/Containerfile
+++ b/tests/containers/tang/Containerfile
@@ -1,8 +1,8 @@
-FROM registry.fedoraproject.org/fedora-minimal:39
+FROM registry.fedoraproject.org/fedora-minimal:40
 
 RUN microdnf -y install tang && microdnf clean all && rm -rf /var/cache/yum
 EXPOSE 80
 
 RUN systemctl enable tangd.socket
 
-CMD ["/sbin/init"]
\ No newline at end of file
+CMD ["/sbin/init"]