diff --git a/plots/scalability/speedup.plt b/plots/scalability/speedup.plt
index 917960e..688b182 100644
--- a/plots/scalability/speedup.plt
+++ b/plots/scalability/speedup.plt
@@ -4,6 +4,7 @@ set output 'speedup.eps'
 
 set nokey
 
+set xlabel "Number of Participating Minions"
 set ylabel "Speedup (S_p)"
 
 set log xy