diff --git a/src/scan.l b/src/scan.l
index 86fe2b77b2..7ad206f56e 100644
--- a/src/scan.l
+++ b/src/scan.l
@@ -7,6 +7,7 @@
 #include <list>
 #include <string>
 #include <algorithm>
+#include <utility>
 #include <sys/stat.h>
 #include <sys/param.h>
 #include <unistd.h>