diff --git a/vncviewer/vncviewer.cxx b/vncviewer/vncviewer.cxx
index 20a0174b8c..46567beb87 100644
--- a/vncviewer/vncviewer.cxx
+++ b/vncviewer/vncviewer.cxx
@@ -519,7 +519,7 @@ createTunnel(const char *gatewayHost, const char *remoteHost,
   setenv("R", rport, 1);
   setenv("L", lport, 1);
   if (!cmd)
-    cmd = "/usr/bin/ssh -f -L \"$L\":\"$H\":\"$R\" \"$G\" sleep 20";
+    cmd = "/usr/bin/ssh -f -L \"$L\":\"$H\":\"$R\" -- \"$G\" sleep 20";
   /* Compatibility with TigerVNC's method. */
   cmd2 = strdup(cmd);
   while ((percent = strchr(cmd2, '%')) != nullptr)