diff --git a/flashchips.c b/flashchips.c
index 294fae1..a1ad445 100644
--- a/flashchips.c
+++ b/flashchips.c
@@ -8092,6 +8092,53 @@
 
 	{
 		.vendor		= "Macronix",
+		.name		= "MX66L51235F",
+		.bustype	= BUS_SPI,
+		.manufacture_id	= MACRONIX_ID,
+		.model_id	= MACRONIX_MX66L51235F,
+		.total_size	= 65536,
+		.page_size	= 256,
+		/* OTP: 512B total; enter 0xB1, exit 0xC1 */
+		.feature_bits	= FEATURE_WRSR_WREN | FEATURE_OTP | FEATURE_4BA_SUPPORT,
+		.four_bytes_addr_funcs =
+		{
+			.set_4ba = spi_enter_4ba_b7, /* enter 4-bytes addressing mode by CMD B7 */
+			.read_nbyte = spi_nbyte_read_4ba,  /* read from 4-bytes addressing mode */
+			.program_byte = spi_byte_program_4ba, /* write from 4-bytes addressing mode */
+			.program_nbyte = spi_nbyte_program_4ba /* write from 4-bytes addressing mode */
+		},
+		.tested		= TEST_OK_PREW,
+		.probe		= probe_spi_rdid,
+		.probe_timing	= TIMING_ZERO,
+		.block_erasers	=
+		{
+			{
+				.eraseblocks = { {4 * 1024, 16384} },
+				.block_erase = spi_block_erase_20_4ba,
+			}, {
+				.eraseblocks = { {32 * 1024, 2048} },
+				.block_erase = spi_block_erase_52_4ba,
+			}, {
+				.eraseblocks = { {64 * 1024, 1024} },
+				.block_erase = spi_block_erase_d8_4ba,
+			}, {
+				.eraseblocks = { {64 * 1024 * 1024, 1} },
+				.block_erase = spi_block_erase_60,
+			}, {
+				.eraseblocks = { {64 * 1024 * 1024, 1} },
+				.block_erase = spi_block_erase_c7,
+			}
+		},
+		/* TODO: security register and SBLK/SBULK; MX25L12835F: configuration register */
+		.printlock	= spi_prettyprint_status_register_bp3_srwd, /* bit6 is quad enable */
+		.unlock		= spi_disable_blockprotect_bp3_srwd,
+		.write		= spi_chip_write_256,
+		.read		= spi_chip_read, /* Fast read (0x0B) supported */
+		.voltage	= {2700, 3600},
+	},
+
+	{
+		.vendor		= "Macronix",
 		.name		= "MX25U1635E",
 		.bustype	= BUS_SPI,
 		.manufacture_id	= MACRONIX_ID,
diff --git a/flashchips.h b/flashchips.h
index 28a155d..bff0c98 100644
--- a/flashchips.h
+++ b/flashchips.h
@@ -482,6 +482,7 @@
 #define MACRONIX_MX25L25635F	0x2019	/* Same as MX25L25639F, but the latter seems to not support REMS */
 #define MACRONIX_MX25L1635D	0x2415
 #define MACRONIX_MX25L1635E	0x2515	/* MX25L1635{E} */
+#define MACRONIX_MX66L51235F	0x201a	/* MX66L51235F */
 #define MACRONIX_MX25U1635E	0x2535
 #define MACRONIX_MX25U3235E	0x2536	/* Same as MX25U6435F */
 #define MACRONIX_MX25U6435E	0x2537	/* Same as MX25U6435F */