diff --git a/osscan.cc b/osscan.cc
index 222620e6d..9bd669258 100644
--- a/osscan.cc
+++ b/osscan.cc
@@ -74,7 +74,7 @@
 #include <time.h>
 
 #include <algorithm>
-#include <list>
+#include <set>
 
 extern NmapOps o;