diff --git a/src/fcatomic.c b/src/fcatomic.c
index b1dc30a..cb5b7a5 100644
--- a/src/fcatomic.c
+++ b/src/fcatomic.c
@@ -56,6 +56,7 @@
 #include <time.h>
 
 #ifdef _WIN32
+#include <direct.h>
 #define mkdir(path,mode) _mkdir(path)
 #endif