diff --git a/start-vnc b/start-vnc
index f609d9bb5fc23f951d71c8053e3e3813c890c532..4c7010ec7410e62f4461476d5b21493a4630558a 100755
--- a/start-vnc
+++ b/start-vnc
@@ -75,7 +75,7 @@ SVNC_CLIENT="vncviewer"
 # More options for the vncserver. TurboVNC on A Mac may produce
 # a 'javax.net.ssl.SSLHandshakeException' in this case adding
 # ' -securitytypes none' to SVNC_SERVER_OPTIONS may help.
-SVNC_SERVER_OPTIONS="-geometry1920x1200"
+SVNC_SERVER_OPTIONS="-geometry 1920x1200"
 
 # Session run time in minutes
 SVNC_RUNTIME=240
@@ -272,6 +272,7 @@ main () {
     parse_options "$@"
     trap clean_up INT QUIT TERM ERR EXIT
 
+    mkdir -p "${HOME}/.ssh"
     ssh_socket_dir="$(mktemp -d "${HOME}/.ssh/socket.XXXXX")"
     ssh_frontend "" "-MNf"
     prepare_vncserver
@@ -289,6 +290,7 @@ main () {
 
     local vnc_port=$((5900+${vnc_display}))
     ssh -o ForwardX11=no \
+        -o StrictHostKeyChecking=accept-new \
         -L "${vnc_port}:localhost:${vnc_port}" \
         -Nf \
         "${SVNC_USERNAME}@${vnc_host}.dkrz.de";