diff --git a/tests/docker/dockerfiles/debian-all-test-cross.docker b/tests/docker/dockerfiles/debian-all-test-cross.docker
index 2beb077fb4..8dc5e1b5de 100644
--- a/tests/docker/dockerfiles/debian-all-test-cross.docker
+++ b/tests/docker/dockerfiles/debian-all-test-cross.docker
@@ -20,8 +20,10 @@ RUN export DEBIAN_FRONTEND=noninteractive && \
 # Add extra build tools and as many cross compilers as we can for testing
 RUN DEBIAN_FRONTEND=noninteractive eatmydata \
         apt install -y --no-install-recommends \
+        bison \
         ccache \
         clang  \
+        flex \
         git \
         ninja-build \
         gcc-aarch64-linux-gnu \