diff --git a/Dockerfile b/Dockerfile
index 8b09973..740a5f6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,7 @@ LABEL maintainer="Frank Denis"
 SHELL ["/bin/sh", "-x", "-c"]
 ENV SERIAL 12
 
-ENV CFLAGS=-Ofast
+ENV CFLAGS=-O3
 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