diff --git a/Dockerfile b/Dockerfile
index 1b8f1de..04fd421 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -4,7 +4,7 @@ SHELL ["/bin/sh", "-x", "-c"]
 ENV SERIAL 12
 
 ENV CFLAGS=-Ofast
-ENV BUILD_DEPS   curl make build-essential git libevent-dev libexpat1-dev autoconf file libssl-dev byacc
+ENV BUILD_DEPS   curl make build-essential git libevent-dev libexpat1-dev autoconf file libssl-dev flex bison
 ENV RUNTIME_DEPS bash util-linux coreutils findutils grep libssl3 ldnsutils libevent-2.1 expat ca-certificates runit runit-helper jed
 
 RUN apt-get update && apt-get -qy dist-upgrade && apt-get -qy clean && \