diff --git a/lib/stm32/common/flash_common_f.c b/lib/stm32/common/flash_common_f.c
index d0a2188a..291fad9b 100644
--- a/lib/stm32/common/flash_common_f.c
+++ b/lib/stm32/common/flash_common_f.c
@@ -27,9 +27,6 @@
 
 void flash_unlock(void)
 {
-	/* Clear the unlock state. */
-	FLASH_CR |= FLASH_CR_LOCK;
-
 	/* Authorize the FPEC access. */
 	FLASH_KEYR = FLASH_KEYR_KEY1;
 	FLASH_KEYR = FLASH_KEYR_KEY2;
diff --git a/lib/stm32/common/flash_common_f24.c b/lib/stm32/common/flash_common_f24.c
index 443d9833..db4ce4c5 100644
--- a/lib/stm32/common/flash_common_f24.c
+++ b/lib/stm32/common/flash_common_f24.c
@@ -96,10 +96,6 @@ reset.
 
 void flash_unlock_option_bytes(void)
 {
-	/* Clear the unlock state. */
-	FLASH_OPTCR |= FLASH_OPTCR_OPTLOCK;
-
-	/* Unlock option bytes. */
 	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY1;
 	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY2;
 }
diff --git a/lib/stm32/f7/flash.c b/lib/stm32/f7/flash.c
index 314343b4..0dcf388b 100644
--- a/lib/stm32/f7/flash.c
+++ b/lib/stm32/f7/flash.c
@@ -91,10 +91,6 @@ reset.
 
 void flash_unlock_option_bytes(void)
 {
-	/* Clear the unlock state. */
-	FLASH_OPTCR |= FLASH_OPTCR_OPTLOCK;
-
-	/* Unlock option bytes. */
 	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY1;
 	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY2;
 }
diff --git a/lib/stm32/l4/flash.c b/lib/stm32/l4/flash.c
index d1fa4663..fd3665aa 100644
--- a/lib/stm32/l4/flash.c
+++ b/lib/stm32/l4/flash.c
@@ -98,10 +98,6 @@ void flash_clear_status_flags(void)
  */
 void flash_unlock_option_bytes(void)
 {
-	/* Clear the unlock state. */
-	FLASH_CR |= FLASH_CR_OPTLOCK;
-
-	/* Unlock option bytes. */
 	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY1;
 	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY2;
 }