diff --git a/sys/dev/usb/quirk/usb_quirk.c b/sys/dev/usb/quirk/usb_quirk.c
index 4090b5683b61..b829ac1d307e 100644
--- a/sys/dev/usb/quirk/usb_quirk.c
+++ b/sys/dev/usb/quirk/usb_quirk.c
@@ -318,6 +318,8 @@ static struct usb_quirk_entry usb_quirks[USB_DEV_QUIRKS_MAX] = {
 	USB_QUIRK(PNY, ATTACHE2, 0x0000, 0xffff, UQ_MSC_FORCE_WIRE_BBB,
 	    UQ_MSC_FORCE_PROTO_SCSI, UQ_MSC_IGNORE_RESIDUE,
 	    UQ_MSC_NO_START_STOP),
+	USB_QUIRK(PROLIFIC, PL2506, 0x0000, 0xffff,
+	    UQ_MSC_NO_SYNC_CACHE),
 	USB_QUIRK_VP(USB_VENDOR_SAMSUNG_TECHWIN,
 	    USB_PRODUCT_SAMSUNG_TECHWIN_DIGIMAX_410, UQ_MSC_FORCE_WIRE_BBB,
 	    UQ_MSC_FORCE_PROTO_SCSI, UQ_MSC_NO_INQUIRY),
diff --git a/sys/dev/usb/usbdevs b/sys/dev/usb/usbdevs
index 64327689bdca..e4128515567d 100644
--- a/sys/dev/usb/usbdevs
+++ b/sys/dev/usb/usbdevs
@@ -2416,6 +2416,7 @@ product PROLIFIC PL2303		0x2303	PL2303 Serial (ATEN/IOGEAR UC232A)
 product PROLIFIC PL2305		0x2305	Parallel printer
 product PROLIFIC ATAPI4		0x2307	ATAPI-4 Controller
 product PROLIFIC PL2501		0x2501	PL2501 Host-Host interface
+product PROLIFIC PL2506		0x2506	PL2506 USB to IDE Bridge
 product PROLIFIC PHAROS		0xaaa0	Prolific Pharos
 product PROLIFIC RSAQ3		0xaaa2	PL2303 Serial Adapter (IODATA USB-RSAQ3)
 product PROLIFIC2 WSIM		0x2001	Willcom WSIM