diff --git a/camlibs/sierra/sierra-usbwrap.c b/camlibs/sierra/sierra-usbwrap.c
index 917f4eae6..a039a64d3 100644
--- a/camlibs/sierra/sierra-usbwrap.c
+++ b/camlibs/sierra/sierra-usbwrap.c
@@ -356,12 +356,12 @@ usb_wrap_DATA (GPPort *dev, unsigned int type, char *sierra_response, int *sierr
    }
    *sierra_len = msg_len - sizeof(*msg);
 
-   msg = (uw_pkout_sierra_hdr_t*)malloc(msg_len);
+   msg = (uw_pkout_sierra_hdr_t*)calloc(msg_len,1);
+
    memset(&cmd, 0, sizeof(cmd));
    cmd.cmd 	= cmdbyte(type, 2);
    cmd.length	= uw_value(msg_len);
 
-   memset(msg, 0, sizeof(msg));
    ret = gp_port_send_scsi_cmd (dev, 0, (char*)&cmd, sizeof(cmd),
    	 sense_buffer, sizeof(sense_buffer), (char*)msg, msg_len);