diff --git a/docker/gpg4win-bullseye/Dockerfile b/docker/gpg4win-bullseye/Dockerfile
index 09e3c7b6..e90fee5f 100644
--- a/docker/gpg4win-bullseye/Dockerfile
+++ b/docker/gpg4win-bullseye/Dockerfile
@@ -1,61 +1,63 @@
 # Dockerfile - docker/gpg4win-bullseye
 # Copyright (C) 2022 g10 Code GmbH
 #
 # Software engineering by Ingo Klöcker <dev@ingo-kloecker.de>
 #
 # This file is part of GnuPG.
 #
 # Gpg4win is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 2 of the License, or
 # (at your option) any later version.
 #
 # Gpg4win is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, see <https://www.gnu.org/licenses/>.
 #
 # SPDX-License-Identifier: GPL-2.0+
 
 FROM debian:bullseye
 
 RUN set -x \
     && apt-get update \
     && apt-get install --no-install-recommends --no-install-suggests -y \
         autoconf \
         automake \
+        bison \
         build-essential \
         cmake \
         docbook-utils \
+        flex \
         gettext \
         ghostscript \
         git \
         gperf \
         gpgrt-tools \
         icoutils \
         imagemagick \
         libboost-dev \
         libgdk-pixbuf2.0-dev \
         libgettextpo-dev \
         libglib2.0-dev \
         libgtk2.0-bin \
         libkf5config-dev \
         libkf5config-dev-bin \
         libkf5coreaddons-dev \
         libxml2-utils \
         mingw-w64 \
         mingw-w64-i686-dev \
         mingw-w64-x86-64-dev \
         nsis \
         stow \
         texinfo \
         texlive \
         texlive-lang-german \
         texlive-latex-extra \
         unzip \
         wget
 
 RUN sed -i /pattern=\"EPS\"/d /etc/ImageMagick-6/policy.xml