diff --git a/libfreefare/tlv.c b/libfreefare/tlv.c
index 9111c9f..e3459f8 100644
--- a/libfreefare/tlv.c
+++ b/libfreefare/tlv.c
@@ -28,6 +28,10 @@
 
 #include "config.h"
 
+#if defined(HAVE_SYS_TYPES_H)
+#  include <sys/types.h>
+#endif
+
 #if defined(HAVE_SYS_ENDIAN_H)
 #  include <sys/endian.h>
 #endif