diff --git a/src/fs-extension-functions.cc b/src/fs-extension-functions.cc
index fdc2338c..35457a3b 100644
--- a/src/fs-extension-functions.cc
+++ b/src/fs-extension-functions.cc
@@ -35,6 +35,8 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <sys/param.h>
+#include <stdlib.h>
 
 #include <string>
 #include <stddef.h>