diff --git a/Dockerfile b/Dockerfile
index f83c17cd..c546ea0f 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -58,6 +58,7 @@ RUN mkdir -p "${EP_DIR}" && chown etherpad:etherpad "${EP_DIR}"
 # the mkdir is needed for configuration of openjdk-11-jre-headless, see
 # https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=863199
 RUN [ -n "${INSTALL_ABIWORD}${INSTALL_SOFFICE}" ] || exit 0; \
+    export DEBIAN_FRONTEND=noninteractive; \
     mkdir -p /usr/share/man/man1 && \
     apt-get -qq update && \
     apt-get -qq install \