diff --git a/embed/boardloader/main.c b/embed/boardloader/main.c
index 00788c5f9..de4710ea9 100644
--- a/embed/boardloader/main.c
+++ b/embed/boardloader/main.c
@@ -75,7 +75,6 @@ static bool copy_sdcard(void)
     uint8_t sectors[] = {
         FLASH_SECTOR_STORAGE_1,
         FLASH_SECTOR_STORAGE_2,
-        FLASH_SECTOR_PIN_AREA,
         FLASH_SECTOR_BOOTLOADER,
         FLASH_SECTOR_FIRMWARE_START,
         7,
@@ -94,8 +93,9 @@ static bool copy_sdcard(void)
         21,
         22,
         FLASH_SECTOR_FIRMWARE_EXTRA_END,
+        FLASH_SECTOR_PIN_AREA,
     };
-    if (!flash_erase_sectors(sectors, 2 + 1 + 1 + 6 + 4 + 7, progress_callback)) {
+    if (!flash_erase_sectors(sectors, 2 + 1 + 6 + 4 + 7 + 1, progress_callback)) {
         display_printf(" failed\n");
         return false;
     }
@@ -153,7 +153,10 @@ int main(void)
 #if PRODUCTION
     flash_set_option_bytes();
     if (!flash_check_option_bytes()) {
-        uint8_t sectors[] = {FLASH_SECTOR_STORAGE_1, FLASH_SECTOR_STORAGE_2};
+        uint8_t sectors[] = {
+            FLASH_SECTOR_STORAGE_1,
+            FLASH_SECTOR_STORAGE_2,
+        };
         flash_erase_sectors(sectors, 2, NULL);
         ensure(0, "wrong option bytes");
     }
diff --git a/embed/bootloader/messages.c b/embed/bootloader/messages.c
index eac92e8d8..a38e802df 100644
--- a/embed/bootloader/messages.c
+++ b/embed/bootloader/messages.c
@@ -356,7 +356,6 @@ int process_msg_WipeDevice(uint8_t iface_num, uint32_t msg_size, uint8_t *buf)
     uint8_t sectors[] = {
         FLASH_SECTOR_STORAGE_1,
         FLASH_SECTOR_STORAGE_2,
-        FLASH_SECTOR_PIN_AREA,
         FLASH_SECTOR_FIRMWARE_START,
         7,
         8,
@@ -374,8 +373,9 @@ int process_msg_WipeDevice(uint8_t iface_num, uint32_t msg_size, uint8_t *buf)
         21,
         22,
         FLASH_SECTOR_FIRMWARE_EXTRA_END,
+        FLASH_SECTOR_PIN_AREA,
     };
-    if (!flash_erase_sectors(sectors, 2 + 1 + 6 + 4 + 7, progress_wipe)) {
+    if (!flash_erase_sectors(sectors, 2 + 6 + 4 + 7 + 1, progress_wipe)) {
         MSG_SEND_INIT(Failure);
         MSG_SEND_ASSIGN_VALUE(code, FailureType_Failure_ProcessError);
         MSG_SEND_ASSIGN_STRING(message, "Could not erase flash");
diff --git a/embed/trezorhal/flash.c b/embed/trezorhal/flash.c
index ccd890a46..8c008dfea 100644
--- a/embed/trezorhal/flash.c
+++ b/embed/trezorhal/flash.c
@@ -3,6 +3,38 @@
 #include <string.h>
 #include "flash.h"
 
+// see docs/memory.md for more information
+
+#define SECTOR_COUNT 24
+
+static const uint32_t SECTOR_TABLE[SECTOR_COUNT + 1] = {
+    [ 0] = 0x08000000, // - 0x08003FFF |  16 KiB
+    [ 1] = 0x08004000, // - 0x08007FFF |  16 KiB
+    [ 2] = 0x08008000, // - 0x0800BFFF |  16 KiB
+    [ 3] = 0x0800C000, // - 0x0800FFFF |  16 KiB
+    [ 4] = 0x08010000, // - 0x0801FFFF |  64 KiB
+    [ 5] = 0x08020000, // - 0x0803FFFF | 128 KiB
+    [ 6] = 0x08040000, // - 0x0805FFFF | 128 KiB
+    [ 7] = 0x08060000, // - 0x0807FFFF | 128 KiB
+    [ 8] = 0x08080000, // - 0x0809FFFF | 128 KiB
+    [ 9] = 0x080A0000, // - 0x080BFFFF | 128 KiB
+    [10] = 0x080C0000, // - 0x080DFFFF | 128 KiB
+    [11] = 0x080E0000, // - 0x080FFFFF | 128 KiB
+    [12] = 0x08100000, // - 0x08103FFF |  16 KiB
+    [13] = 0x08104000, // - 0x08107FFF |  16 KiB
+    [14] = 0x08108000, // - 0x0810BFFF |  16 KiB
+    [15] = 0x0810C000, // - 0x0810FFFF |  16 KiB
+    [16] = 0x08110000, // - 0x0811FFFF |  64 KiB
+    [17] = 0x08120000, // - 0x0813FFFF | 128 KiB
+    [18] = 0x08140000, // - 0x0815FFFF | 128 KiB
+    [19] = 0x08160000, // - 0x0817FFFF | 128 KiB
+    [20] = 0x08180000, // - 0x0819FFFF | 128 KiB
+    [21] = 0x081A0000, // - 0x081BFFFF | 128 KiB
+    [22] = 0x081C0000, // - 0x081DFFFF | 128 KiB
+    [23] = 0x081E0000, // - 0x081FFFFF | 128 KiB
+    [24] = 0x08200000, // last element - not a valid sector
+};
+
 int flash_init(void)
 {
     return 0;
@@ -40,6 +72,13 @@ bool flash_erase_sectors(const uint8_t *sectors, int len, void (*progress)(int p
             flash_lock();
             return false;
         }
+        // check whether the sector was really deleted (contains only 0xFF)
+        uint32_t addr_start = SECTOR_TABLE[sectors[i]], addr_end = SECTOR_TABLE[sectors[i] + 1];
+        for (uint32_t addr = addr_start; addr < addr_end; addr += 4) {
+            if (*((const uint32_t *)addr) != 0xFFFFFFFF) {
+                return false;
+            }
+        }
         if (progress) {
             progress(i + 1, len);
         }
diff --git a/embed/trezorhal/flash.h b/embed/trezorhal/flash.h
index ed40c24c6..84086ff12 100644
--- a/embed/trezorhal/flash.h
+++ b/embed/trezorhal/flash.h
@@ -38,7 +38,6 @@
 //                                          22
 //                                          23
 #define FLASH_SECTOR_FIRMWARE_EXTRA_END     23
-#define FLASH_SECTOR_LAST                   23
 
 int flash_init(void);