diff --git a/perl-xCAT/xCAT/PPCboot.pm b/perl-xCAT/xCAT/PPCboot.pm
index 1e80eb09c..e72e5ede5 100644
--- a/perl-xCAT/xCAT/PPCboot.pm
+++ b/perl-xCAT/xCAT/PPCboot.pm
@@ -135,6 +135,9 @@ sub do_rnetboot {
     if ( !-x $cmd ) {
         return( [RC_ERROR,"Command not installed: $cmd"] );
     }
+    if (!-x "/usr/bin/expect" ) {
+        return( [RC_ERROR,"Command not installed: /usr/bin/expect"] );
+    }
     #######################################
     # Save user name and passwd of hcp to
     # environment variables.