diff --git a/arch/arm/boot/dts/stm32mp131.dtsi b/arch/arm/boot/dts/stm32mp131.dtsi
index accc3824f7e9..99d88096959e 100644
--- a/arch/arm/boot/dts/stm32mp131.dtsi
+++ b/arch/arm/boot/dts/stm32mp131.dtsi
@@ -527,6 +527,7 @@ bsec: efuse@5c005000 {
 
 			part_number_otp: part_number_otp@4 {
 				reg = <0x4 0x2>;
+				bits = <0 12>;
 			};
 			ts_cal1: calib@5c {
 				reg = <0x5c 0x2>;