diff --git a/camlibs/ptp2/usb.c b/camlibs/ptp2/usb.c
index cee7bd6c8..929ef638c 100644
--- a/camlibs/ptp2/usb.c
+++ b/camlibs/ptp2/usb.c
@@ -261,7 +261,7 @@ ptp_usb_getdata (PTPParams* params, PTPContainer* ptp, PTPDataHandler *handler)
 	uint16_t ret;
 	PTPUSBBulkContainer usbdata;
 	unsigned char	*data = NULL;
-	uint32_t	bytes_to_read, bytes_read;
+	uint32_t	bytes_to_read = 0, bytes_read = 0;
 	Camera		*camera = ((PTPData *)params->data)->camera;
 	int		report_progress, progress_id = 0, do_retry = TRUE, res = GP_OK;
 	GPContext *context = ((PTPData *)params->data)->context;