diff --git a/src/spiFlash.cpp b/src/spiFlash.cpp
index 2c43fac..07fadcb 100644
--- a/src/spiFlash.cpp
+++ b/src/spiFlash.cpp
@@ -334,6 +334,9 @@ int SPIFlash::erase_and_prog(int base_addr, uint8_t *data, int len)
 	int size = 0;
 	for (int addr = 0; addr < len; addr += size, ptr+=size) {
 		size = (addr + 256 > len)?(len-addr) : 256;
+		if ((_jedec_id >> 8) == 0xbf258d) {
+			size = 1;
+		}
 		if (write_page(base_addr + addr, ptr, size) == -1)
 			return -1;
 		progress.display(addr);
diff --git a/src/spiFlashdb.hpp b/src/spiFlashdb.hpp
index 077a6d9..e4b2c21 100644
--- a/src/spiFlashdb.hpp
+++ b/src/spiFlashdb.hpp
@@ -15,7 +15,7 @@ typedef enum {
 	STATR = 0,  /* status register */
 	FUNCR = 1,  /* function register */
 	CONFR = 2,  /* configuration register */
-	NONER = 99, /* configuration register */
+	NONER = 99, /* "none" register */
 } tb_loc_t;
 
 typedef struct {
@@ -125,6 +125,19 @@ static std::map <uint32_t, flash_t> flash_list = {
 		.bp_len = 4,
 		.bp_offset = {(1 << 2), (1 << 3), (1 << 4), (1 << 6)}}
 	},
+	{0xbf258d, {
+		.manufacturer = "microchip",
+		.model = "SST25VF040B",
+		.nr_sector = 8,
+		.sector_erase = true,
+		.subsector_erase = true,
+		.has_extended = false,
+		.tb_otp = false,
+		.tb_offset = 0,
+		.tb_register = NONER,
+		.bp_len = 4,
+		.bp_offset = {(1 << 2), (1 << 3), (1 << 4), (1 << 5)}}
+	},
 	{0xBF2642, {
 		.manufacturer = "microchip",
 		.model = "SST26VF032B",