diff --git a/dist/tools/nrf52_resetpin_cfg/README.md b/dist/tools/nrf52_resetpin_cfg/README.md
index e7634c924e..fb5e4213eb 100644
--- a/dist/tools/nrf52_resetpin_cfg/README.md
+++ b/dist/tools/nrf52_resetpin_cfg/README.md
@@ -5,6 +5,10 @@ Simply compile, flash, and run this tool on your nRF52x-based board. It will
 program the given `RESET_PIN` into the NRF_UICR->PSELRESET registers, hence
 allowing for hardware resets using a button connected to that pin.
 
+> [!WARNING]
+> This tool only works with early nRF52 chips with build codes before Fxx.
+> Later build codes automatically erase the UICR register on each flashing
+> operation.
 
 Context
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