diff --git a/ion/src/device/flash.cpp b/ion/src/device/flash.cpp
index 7dea241d0..b0260845c 100644
--- a/ion/src/device/flash.cpp
+++ b/ion/src/device/flash.cpp
@@ -54,13 +54,14 @@ static void typed_memcpy(uint8_t * source, uint8_t * destination, size_t length)
 }
 
 int SectorAtAddress(uint32_t address) {
-  uint32_t sectorAddresses[NumberOfSectors] = {
+  uint32_t sectorAddresses[NumberOfSectors+1] = {
     0x08000000, 0x08004000, 0x08008000, 0x0800C000,
     0x08010000, 0x08020000, 0x08040000, 0x08060000,
-    0x08080000, 0x080A0000, 0x080C0000, 0x080E0000
+    0x08080000, 0x080A0000, 0x080C0000, 0x080E0000,
+    0x08100000
   };
   for (int i=0; i<NumberOfSectors; i++) {
-    if (sectorAddresses[i] == address) {
+    if (address >= sectorAddresses[i] && address < sectorAddresses[i+1]) {
       return i;
     }
   }