diff --git a/Dockerfile b/Dockerfile
index 34bc2ab..7f3fcd8 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -31,7 +31,8 @@ RUN \
  mkdir /root-out && \
  tar xf \
 	/rootfs.tar.xz -C \
-	/root-out
+	/root-out && \
+ sed -i -e 's/^root::/root:!:/' /root-out/etc/shadow
 
 # Runtime stage
 FROM scratch
diff --git a/Dockerfile.aarch64 b/Dockerfile.aarch64
index 8118301..0830243 100644
--- a/Dockerfile.aarch64
+++ b/Dockerfile.aarch64
@@ -31,7 +31,8 @@ RUN \
  mkdir /root-out && \
  tar xf \
 	/rootfs.tar.xz -C \
-	/root-out
+	/root-out && \
+ sed -i -e 's/^root::/root:!:/' /root-out/etc/shadow
 
 # Runtime stage
 FROM scratch
diff --git a/Dockerfile.armhf b/Dockerfile.armhf
index 1f32fd8..ee2db3d 100644
--- a/Dockerfile.armhf
+++ b/Dockerfile.armhf
@@ -31,7 +31,8 @@ RUN \
  mkdir /root-out && \
  tar xf \
 	/rootfs.tar.xz -C \
-	/root-out
+	/root-out && \
+ sed -i -e 's/^root::/root:!:/' /root-out/etc/shadow
 
 # Runtime stage
 FROM scratch