diff --git a/Dockerfile b/Dockerfile
index d4daf74..0e97349 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 1e5704e..f78977c 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 139410f..5070ba6 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