diff --git a/Dockerfile b/Dockerfile
index a2a33d1..c846d61 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -10,7 +10,8 @@ RUN set -eux; \
         net-tools \
         screen \
     ; \
-    rm -rf /var/lib/apt/lists/*
+    rm -rf /var/lib/apt/lists/* \
+    rm /etc/ssh/ssh_host_*key*
 
 ADD start.sh /
 
diff --git a/start.sh b/start.sh
index 1e8c195..2f949ec 100755
--- a/start.sh
+++ b/start.sh
@@ -45,4 +45,11 @@ while [ "$USERADD" != "$i" ] ;do
     useradd --home-dir "$BASE_DIR/$USER_NAME" --uid "$USER_UID" --gid "$USER_GID" "$USER_NAME"
 done
 
+if [ -z "$(find /etc/ssh/ -maxdepth 1 -name 'ssh_host_*_key' -print -quit)" ]; then
+    echo "Creating SSH2 ED25519 key; this may take some time ..."
+    ssh-keygen -q -f /etc/ssh/ssh_host_ed25519_key -N '' -t ed25519
+    ssh-keygen -l -f /etc/ssh/ssh_host_ed25519_key.pub
+    echo "HostKey /etc/ssh/ssh_host_ed25519_key" >> /etc/ssh/sshd_config
+fi
+
 exec /usr/sbin/sshd -D -e