diff --git a/ports/nrf/boards/common.ld b/ports/nrf/boards/common.ld
index d2e5eef762..866336fa02 100644
--- a/ports/nrf/boards/common.ld
+++ b/ports/nrf/boards/common.ld
@@ -81,3 +81,5 @@ SECTIONS
 /* Define heap and stack areas */
 _ram_end = ORIGIN(RAM) + LENGTH(RAM);
 _estack = ORIGIN(RAM) + LENGTH(RAM);
+_unused_flash_start = (_sidata + (_edata - _sdata));
+_unused_flash_len = (ORIGIN(FLASH_TEXT) + LENGTH(FLASH_TEXT)) - _unused_flash_start;