diff --git a/sanei/sanei_usb.c b/sanei/sanei_usb.c
index 9323a58bf..0ec99bd1e 100644
--- a/sanei/sanei_usb.c
+++ b/sanei/sanei_usb.c
@@ -91,7 +91,7 @@ device_list_type;
 static device_list_type devices[MAX_DEVICES];
 
 #ifdef HAVE_LIBUSB
-int libusb_timeout = 30 * 1000;	/* 30 seconds */
+static int libusb_timeout = 30 * 1000;	/* 30 seconds */
 #endif /* HAVE_LIBUSB */
 
 #if defined (__linux__)