diff --git a/ChangeLog b/ChangeLog
index 419c8984e..61723f05d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -2,6 +2,7 @@
 
 	* backend/test.c doc/descriptions/test.desc: Fixed initial value
 	  for --fixed-constraint-range (bug #300388).
+	* include/sane/sanei_usb.h: Include stdlib.h for size_t.
 
 2003-12-18  Gerhard Jaeger <gerhard@gjaeger.de>
 	* doc/sane-plustek.man: new version, minor fixes
diff --git a/include/sane/sanei_usb.h b/include/sane/sanei_usb.h
index 578aa6285..9b16aa73f 100644
--- a/include/sane/sanei_usb.h
+++ b/include/sane/sanei_usb.h
@@ -64,6 +64,8 @@
 #include "../include/sane/config.h"
 #include "../include/sane/sane.h"
 
+#include <stdlib.h> /* for size_t */
+
 /* USB spec defines */
 #ifndef USB_CLASS_PER_INTERFACE
 /* Also defined in libusb */