diff --git a/rules/makerlsfile.cpp b/rules/makerlsfile.cpp
index e51eba02..822c721d 100644
--- a/rules/makerlsfile.cpp
+++ b/rules/makerlsfile.cpp
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <iostream>
 #include <fstream>
+#include <string>
 
 using namespace std;