diff --git a/platforms/chibios/drivers/wear_leveling/wear_leveling_efl.c b/platforms/chibios/drivers/wear_leveling/wear_leveling_efl.c
index 1a331e1a474..0df982b83ac 100644
--- a/platforms/chibios/drivers/wear_leveling/wear_leveling_efl.c
+++ b/platforms/chibios/drivers/wear_leveling/wear_leveling_efl.c
@@ -83,13 +83,21 @@ bool backing_store_init(void) {
 #else // defined(WEAR_LEVELING_EFL_FIRST_SECTOR)
 
     // Work out how many sectors we want to use, working backwards from the end of the flash
-    flash_sector_t last_sector = desc->sectors_count - WEAR_LEVELING_EFL_OMIT_LAST_SECTOR_COUNT;
+    flash_sector_t last_sector = desc->sectors_count;
 
     // skip sectors that are past the actual flash size
-    while (flashGetSectorOffset(flash, last_sector) >= flash_size) {
-        last_sector--;
+    while (flashGetSectorOffset(flash, last_sector - 1) >= flash_size) {
+        if (--last_sector == 0) {
+            chSysHalt("No sector in available flash range");
+        }
     }
 
+    if (WEAR_LEVELING_EFL_OMIT_LAST_SECTOR_COUNT >= last_sector) {
+        chSysHalt("Last sector intended to be used with wear_leveling is beyond available flash descriptor range");
+    }
+
+    last_sector -= WEAR_LEVELING_EFL_OMIT_LAST_SECTOR_COUNT;
+
     for (flash_sector_t i = 0; i < last_sector; ++i) {
         first_sector = last_sector - i - 1;
         counter += flashGetSectorSize(flash, first_sector);
@@ -100,6 +108,10 @@ bool backing_store_init(void) {
         }
     }
 
+    if (counter < WEAR_LEVELING_BACKING_SIZE) {
+        chSysHalt("Not enough flash is available for the requested wear_leveling size");
+    }
+
 #endif // defined(WEAR_LEVELING_EFL_FIRST_SECTOR)
 
     return true;