diff --git a/sparsebundlefs.cpp b/sparsebundlefs.cpp
index 70d0f24..005c5f7 100644
--- a/sparsebundlefs.cpp
+++ b/sparsebundlefs.cpp
@@ -6,6 +6,7 @@
 #include <stdlib.h>
 #include <syslog.h>
 #include <string.h>
+#include <unistd.h>
 #include <sys/resource.h>
 
 #include <algorithm>