diff --git a/scripts/mosh b/scripts/mosh
index 6ca7a27..8f14abe 100755
--- a/scripts/mosh
+++ b/scripts/mosh
@@ -154,7 +154,11 @@ if ( $pid == 0 ) { # child
   }
   waitpid $pid, 0;
 
-  if ( not defined $ip or not defined $port ) {
+  if ( not defined $ip ) {
+      die "$0: Did not find remote IP address (is SSH ProxyCommand disabled?).\n";
+  }
+
+  if ( not defined $key or not defined $port ) {
     die "$0: Did not find mosh server startup message.\n";
   }