diff --git a/plat/st/stm32mp1/stm32mp1_def.h b/plat/st/stm32mp1/stm32mp1_def.h
index 0fa6c73..6530957 100644
--- a/plat/st/stm32mp1/stm32mp1_def.h
+++ b/plat/st/stm32mp1/stm32mp1_def.h
@@ -427,7 +427,7 @@
 
 /* OTP labels */
 #define CFG0_OTP			"cfg0_otp"
-#define PART_NUMBER_OTP			"part_number_otp"
+#define PART_NUMBER_OTP			"part-number-otp"
 #if STM32MP15
 #define PACKAGE_OTP			"package_otp"
 #endif