diff --git a/feedGnuplot.pl b/feedGnuplot.pl
index 41b5356..bd45590 100755
--- a/feedGnuplot.pl
+++ b/feedGnuplot.pl
@@ -351,8 +351,9 @@ sub mainThread {
         }
       }
 
-      elsif($options{"stream"} && defined $xlast)
+      elsif($options{"stream"})
       {
+        # only redraw a streaming plot if there's new data to plot
         next unless $haveNewData;
         $haveNewData = undef;