diff --git a/contrib/build-linux/appimage/Dockerfile_ub2004 b/contrib/build-linux/appimage/Dockerfile_ub2004
index 64516d82b645..6d560f5e9bdb 100644
--- a/contrib/build-linux/appimage/Dockerfile_ub2004
+++ b/contrib/build-linux/appimage/Dockerfile_ub2004
@@ -56,6 +56,7 @@ RUN echo deb ${UBUNTU_MIRROR} ${UBUNTUDIST} main restricted universe multiverse
         libssl-dev=1.1.1f-1ubuntu2.19 \
         rustc=1.66.1+dfsg0ubuntu1~llvm-0ubuntu0.20.04 \
         cargo=0.67.1+ds0ubuntu0.libgit2-0ubuntu0.20.04.2 \
+        g++=4:9.3.0-1ubuntu2 \
         && \
     rm -rf /var/lib/apt/lists/* && \
     apt-get autoremove -y && \