diff --git a/os/hal/ports/STM32/STM32G0xx/hal_efl_lld.c b/os/hal/ports/STM32/STM32G0xx/hal_efl_lld.c
index 0d78eed3e..20af8885e 100644
--- a/os/hal/ports/STM32/STM32G0xx/hal_efl_lld.c
+++ b/os/hal/ports/STM32/STM32G0xx/hal_efl_lld.c
@@ -143,7 +143,7 @@ static inline size_t stm32_flash_get_size(void) {
 static inline bool stm32_flash_dual_bank(EFlashDriver *eflp) {
 
 #if STM32_FLASH_NUMBER_OF_BANKS > 1
-  return ((eflp->flash->SR & (FLASH_OPTR_DBANK | FLASH_OPTR_DB1M)) != 0U);
+#error "Device settings incorrectly configured - single bank mode only supported"
 #endif
   (void)eflp;
   return false;
@@ -588,7 +588,8 @@ flash_error_t efl_lld_verify_erase(void *instance, flash_sector_t sector) {
   devp->state = FLASH_READ;
 
   /* Scanning the sector space.*/
-  for (i = 0U; i < bank->sectors_size / sizeof(uint32_t); i++) {
+  uint32_t sector_size = flashGetSectorSize(getBaseFlash(devp), sector);
+  for (i = 0U; i < sector_size / sizeof(uint32_t); i++) {
     if (*address != 0xFFFFFFFFU) {
       err = FLASH_ERROR_VERIFY;
       break;
diff --git a/os/hal/ports/STM32/STM32L4xx+/hal_efl_lld.c b/os/hal/ports/STM32/STM32L4xx+/hal_efl_lld.c
index 5b7c87b34..cccef0438 100644
--- a/os/hal/ports/STM32/STM32L4xx+/hal_efl_lld.c
+++ b/os/hal/ports/STM32/STM32L4xx+/hal_efl_lld.c
@@ -167,7 +167,7 @@ static inline size_t stm32_flash_get_size(void) {
 static inline bool stm32_flash_dual_bank(EFlashDriver *eflp) {
 
 #if STM32_FLASH_NUMBER_OF_BANKS > 1
-  return ((eflp->flash->SR & (FLASH_OPTR_DBANK | FLASH_OPTR_DB1M)) != 0U);
+  return ((eflp->flash->OPTR & (FLASH_OPTR_DBANK | FLASH_OPTR_DB1M)) != 0U);
 #endif
   return false;
 }
@@ -603,7 +603,7 @@ flash_error_t efl_lld_verify_erase(void *instance, flash_sector_t sector) {
     return FLASH_BUSY_ERASING;
   }
 
-  /* Address of the sector in the selected bank.*/
+  /* Address of the sector in the bank.*/
   address = (uint32_t *)(bank->address +
                         flashGetSectorOffset(getBaseFlash(devp), sector));
 
@@ -611,7 +611,8 @@ flash_error_t efl_lld_verify_erase(void *instance, flash_sector_t sector) {
   devp->state = FLASH_READ;
 
   /* Scanning the sector space.*/
-  for (i = 0U; i < bank->sectors_size / sizeof(uint32_t); i++) {
+  uint32_t sector_size = flashGetSectorSize(getBaseFlash(devp), sector);
+  for (i = 0U; i < sector_size / sizeof(uint32_t); i++) {
     if (*address != 0xFFFFFFFFU) {
       err = FLASH_ERROR_VERIFY;
       break;