diff --git a/docker/proton.Dockerfile.in b/docker/proton.Dockerfile.in
index dd1e461b..5b853fd7 100644
--- a/docker/proton.Dockerfile.in
+++ b/docker/proton.Dockerfile.in
@@ -52,11 +52,13 @@ RUN bash -c 'mkdir -p /usr/lib/ccache && ls /usr/bin/{,*-}{cc,c++,gcc,g++}{,-[0-
 ENV PATH=/usr/lib/ccache:$PATH
 
 RUN apt-get install -y \
+  fontforge \
   libxpresent-dev \
   libxpresent-dev:i386 \
   python3-pefile \
   libcapstone-dev \
   libcapstone-dev:i386 \
+  libutfcpp-dev \
   nasm \
   yasm \
 && rm -rf /opt/usr/share/doc /opt/usr/share/info /opt/usr/share/man \