diff --git a/gen/configfile.cpp b/gen/configfile.cpp
index 30dd4605..3459d6a1 100644
--- a/gen/configfile.cpp
+++ b/gen/configfile.cpp
@@ -1,6 +1,7 @@
 #include <iostream>
 #include <string>
 #include <cassert>
+#include <string.h>
 
 #include "llvm/System/Path.h"