diff --git a/Dockerfile b/Dockerfile
index 2269cdde..7548e5f2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,7 +9,7 @@
 
 FROM alpine:3.16
 
-ENV SWAN_VER 4.7
+ENV SWAN_VER 4.9
 WORKDIR /opt/src
 
 RUN set -x \
@@ -23,8 +23,7 @@ RUN set -x \
     && tar xzf libreswan.tar.gz \
     && rm -f libreswan.tar.gz \
     && cd "libreswan-${SWAN_VER}" \
-    && printf 'WERROR_CFLAGS=-w -s\nUSE_DNSSEC=false\nUSE_DH2=true\n' > Makefile.inc.local \
-    && printf 'FINALNSSDIR=/etc/ipsec.d\nUSE_GLIBC_KERN_FLIP_HEADERS=true\n' >> Makefile.inc.local \
+    && printf 'WERROR_CFLAGS=-w -s\nUSE_DNSSEC=false\nUSE_DH2=true\nFINALNSSDIR=/etc/ipsec.d\n' > Makefile.inc.local \
     && make -s base \
     && make -s install-base \
     && cd /opt/src \
diff --git a/Dockerfile.debian b/Dockerfile.debian
index 31c91810..cd26f36d 100644
--- a/Dockerfile.debian
+++ b/Dockerfile.debian
@@ -9,7 +9,7 @@
 
 FROM debian:bullseye-slim
 
-ENV SWAN_VER 4.7
+ENV SWAN_VER 4.9
 WORKDIR /opt/src
 
 RUN apt-get -yqq update \