diff --git a/src/file.cpp b/src/file.cpp
index 1a864dc..24c0f72 100644
--- a/src/file.cpp
+++ b/src/file.cpp
@@ -7,6 +7,7 @@
 #include <cassert>
 
 #include <sys/file.h>
+#include <fcntl.h>
 #include <unistd.h>
 #include <dirent.h>
 
diff --git a/test/file_test.cpp b/test/file_test.cpp
index 42be85f..b216231 100644
--- a/test/file_test.cpp
+++ b/test/file_test.cpp
@@ -2,6 +2,7 @@
 #include <iostream>
 #include "doctest.h"
 #include <unistd.h>
+#include <fcntl.h>
 #include <sys/file.h>
 #include <iostream>
 #include <fstream>