Index: src/unionfs.h
--- src/unionfs.h.orig
+++ src/unionfs.h
@@ -7,6 +7,8 @@
 #ifndef UNIONFS_H
 #define UNIONFS_H
 
+#include <pthread.h>
+
 #define PATHLEN_MAX 1024
 #define HIDETAG "_HIDDEN~"
 
