diff --git a/include/darknet.h b/include/darknet.h
index 986d4309..3f5e9b74 100644
--- a/include/darknet.h
+++ b/include/darknet.h
@@ -1,6 +1,7 @@
 #ifndef DARKNET_API
 #define DARKNET_API
 #include <stdlib.h>
+#include <pthread.h>
 
 extern int gpu_index;