diff --git a/libztex.c b/libztex.c
index 9ae421e5..ae39829d 100644
--- a/libztex.c
+++ b/libztex.c
@@ -1,5 +1,5 @@
 /**
- *   libztex.c - Ztex 1.15x fpga board support library
+ *   libztex.c - Ztex 1.15x/1.15y fpga board support library
  *
  *   Copyright (c) 2012 nelisky.btc@gmail.com
  *   Copyright (c) 2012 Denis Ahrens <denis@h3q.com>
@@ -105,7 +105,6 @@ static enum check_result libztex_checkDevice(struct libusb_device *dev)
 	int i, ret = CHECK_ERROR, err, cnt;
 	size_t got_bytes, length;
 	unsigned char buf[64], *fw_buf;
-	char *firmware = "ztex_ufm1_15y1.bin";
 
 	err = libusb_get_device_descriptor(dev, &desc);
 	if (unlikely(err != 0)) {
@@ -145,9 +144,8 @@ static enum check_result libztex_checkDevice(struct libusb_device *dev)
 	switch(buf[7])
 	{
 		case 13:
-			applog(LOG_ERR, "Found ztex board 1.15d or 1.15x but currently unsupported!");
-			ret = CHECK_IS_NOT_ZTEX;
-			goto done;
+			applog(LOG_ERR, "Found ztex board 1.15d or 1.15x");
+			break;
 		case 15:
 			applog(LOG_ERR, "Found ztex board 1.15y");
 			break;
@@ -163,7 +161,41 @@ static enum check_result libztex_checkDevice(struct libusb_device *dev)
 		goto done;
 	}
 
-	applog(LOG_ERR, "Found dummy firmware, trying to send mining firmware: %s", firmware);
+	applog(LOG_ERR, "Found dummy firmware, trying to send mining firmware");
+
+	char productString[32];
+
+	cnt = libztex_get_string_descriptor_ascii(hndl, desc.iProduct, productString, sizeof(productString));
+	if (unlikely(cnt < 0)) {
+		applog(LOG_ERR, "Ztex check device: Failed to read device productString with err %d", cnt);
+		return cnt;
+	}
+
+	applog(LOG_ERR, "productString: %s", productString);
+
+	unsigned char productID2 = buf[7];
+	char *firmware = NULL;
+
+	if (strcmp("USB-FPGA Module 1.15d (default)", productString) == 0 && productID2 == 13)
+	{
+		firmware = "ztex_ufm1_15d4.bin";
+	}
+	else if (strcmp("USB-FPGA Module 1.15x (default)", productString) == 0 && productID2 == 13)
+	{
+		firmware = "ztex_ufm1_15d4.bin";
+	}
+	else if (strcmp("USB-FPGA Module 1.15y (default)", productString) == 0 && productID2 == 15)
+	{
+		firmware = "ztex_ufm1_15y1.bin";
+	}
+
+	if (firmware == NULL)
+	{
+		applog(LOG_ERR, "could not figure out which firmware to use");
+		goto done;
+	}
+
+	applog(LOG_ERR, "Mining firmware filename: %s", firmware);
 
 	fp = open_bitstream("ztex", firmware);
 	if (!fp) {