--- a/nDPI/src/include/linux_compat.h
+++ b/nDPI/src/include/linux_compat.h
@@ -42,6 +42,8 @@
 #endif
 #endif
 
+#include <sys/types.h>
+
 #pragma pack(push, 1)  /* push current alignment to stack */
 #pragma pack(1)     /* set alignment to 1 byte boundary */