diff --git a/include/libopencm3/stm32/common/flash_common_all.h b/include/libopencm3/stm32/common/flash_common_all.h
index 00232224..ad7b5560 100644
--- a/include/libopencm3/stm32/common/flash_common_all.h
+++ b/include/libopencm3/stm32/common/flash_common_all.h
@@ -65,4 +65,10 @@ void flash_lock(void);
  */
 void flash_unlock(void);
 
+/** Unlock the Option Byte Access.
+ * This enables write access to the option bytes. It is locked by default on
+ * reset.
+ */
+void flash_unlock_option_bytes(void);
+
 END_DECLS
\ No newline at end of file
diff --git a/include/libopencm3/stm32/common/flash_common_f01.h b/include/libopencm3/stm32/common/flash_common_f01.h
index e0d309e0..e4f7d60f 100644
--- a/include/libopencm3/stm32/common/flash_common_f01.h
+++ b/include/libopencm3/stm32/common/flash_common_f01.h
@@ -95,6 +95,9 @@
 #define FLASH_KEYR_KEY1			((uint32_t)0x45670123)
 #define FLASH_KEYR_KEY2			((uint32_t)0xcdef89ab)
 
+#define FLASH_OPTKEYR_KEY1		FLASH_KEYR_KEY1
+#define FLASH_OPTKEYR_KEY2		FLASH_KEYR_KEY2
+
 /* --- Function prototypes ------------------------------------------------- */
 
 BEGIN_DECLS
@@ -108,7 +111,6 @@ void flash_program_word(uint32_t address, uint32_t data);
 void flash_program_half_word(uint32_t address, uint16_t data);
 void flash_erase_page(uint32_t page_address);
 void flash_erase_all_pages(void);
-void flash_unlock_option_bytes(void);
 void flash_erase_option_bytes(void);
 void flash_program_option_bytes(uint32_t address, uint16_t data);
 
diff --git a/include/libopencm3/stm32/common/flash_common_f24.h b/include/libopencm3/stm32/common/flash_common_f24.h
index 92494bfb..647f8413 100644
--- a/include/libopencm3/stm32/common/flash_common_f24.h
+++ b/include/libopencm3/stm32/common/flash_common_f24.h
@@ -112,7 +112,6 @@
 
 BEGIN_DECLS
 
-void flash_unlock_option_bytes(void);
 void flash_lock_option_bytes(void);
 void flash_clear_pgserr_flag(void);
 void flash_clear_wrperr_flag(void);
diff --git a/include/libopencm3/stm32/common/flash_common_l01.h b/include/libopencm3/stm32/common/flash_common_l01.h
index 8333df57..64f2f6a5 100644
--- a/include/libopencm3/stm32/common/flash_common_l01.h
+++ b/include/libopencm3/stm32/common/flash_common_l01.h
@@ -118,7 +118,6 @@ void flash_unlock_pecr(void);
 void flash_lock_pecr(void);
 void flash_unlock_progmem(void);
 void flash_lock_progmem(void);
-void flash_unlock_option_bytes(void);
 void flash_lock_option_bytes(void);
 
 void eeprom_program_word(uint32_t address, uint32_t data);
diff --git a/include/libopencm3/stm32/f3/flash.h b/include/libopencm3/stm32/f3/flash.h
index f4024c50..d73d215a 100644
--- a/include/libopencm3/stm32/f3/flash.h
+++ b/include/libopencm3/stm32/f3/flash.h
@@ -72,6 +72,10 @@
 #define FLASH_CR_PER			(1 << 1)
 #define FLASH_CR_PG			(1 << 0)
 
+/* F3 uses the same keys for option bytes */
+#define FLASH_OPTKEYR_KEY1		FLASH_KEYR_KEY1
+#define FLASH_OPTKEYR_KEY2		FLASH_KEYR_KEY2
+
 BEGIN_DECLS
 
 
diff --git a/include/libopencm3/stm32/f7/flash.h b/include/libopencm3/stm32/f7/flash.h
index 93a8f7e8..9b9cb120 100644
--- a/include/libopencm3/stm32/f7/flash.h
+++ b/include/libopencm3/stm32/f7/flash.h
@@ -157,7 +157,6 @@ BEGIN_DECLS
 void flash_clear_pgperr_flag(void);
 void flash_wait_for_last_operation(void);
 
-void flash_unlock_option_bytes(void);
 void flash_lock_option_bytes(void);
 void flash_clear_erserr_flag(void);
 void flash_clear_wrperr_flag(void);
diff --git a/include/libopencm3/stm32/l4/flash.h b/include/libopencm3/stm32/l4/flash.h
index c92e95cc..be790d7d 100644
--- a/include/libopencm3/stm32/l4/flash.h
+++ b/include/libopencm3/stm32/l4/flash.h
@@ -228,7 +228,6 @@ void flash_clear_pgserr_flag(void);
 void flash_clear_pgaerr_flag(void);
 void flash_clear_wrperr_flag(void);
 void flash_clear_status_flags(void);
-void flash_unlock_option_bytes(void);
 void flash_lock_option_bytes(void);
 void flash_program_word(uint32_t address, uint32_t data);
 void flash_program(uint32_t address, uint8_t *data, uint32_t len);
diff --git a/lib/stm32/common/flash_common_all.c b/lib/stm32/common/flash_common_all.c
index f85fac1e..98821796 100644
--- a/lib/stm32/common/flash_common_all.c
+++ b/lib/stm32/common/flash_common_all.c
@@ -43,6 +43,10 @@ void flash_set_ws(uint32_t ws)
 	FLASH_ACR = reg32;
 }
 
-
+void flash_unlock_option_bytes(void)
+{
+	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY1;
+	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY2;
+}
 
 /*@}*/
diff --git a/lib/stm32/common/flash_common_f01.c b/lib/stm32/common/flash_common_f01.c
index fc621388..2520a66c 100644
--- a/lib/stm32/common/flash_common_f01.c
+++ b/lib/stm32/common/flash_common_f01.c
@@ -85,20 +85,6 @@ void flash_program_word(uint32_t address, uint32_t data)
 	flash_program_half_word(address+2, (uint16_t)(data>>16));
 }
 
-/*---------------------------------------------------------------------------*/
-/** @brief Unlock the Option Byte Access
-
-This enables write access to the option bytes. It is locked by default on
-reset.
-*/
-
-void flash_unlock_option_bytes(void)
-{
-	/* F1 uses same keys for flash and option */
-	FLASH_OPTKEYR = FLASH_KEYR_KEY1;
-	FLASH_OPTKEYR = FLASH_KEYR_KEY2;
-}
-
 /*---------------------------------------------------------------------------*/
 /** @brief Erase All Option Bytes
 
diff --git a/lib/stm32/common/flash_common_f24.c b/lib/stm32/common/flash_common_f24.c
index db4ce4c5..096409c7 100644
--- a/lib/stm32/common/flash_common_f24.c
+++ b/lib/stm32/common/flash_common_f24.c
@@ -87,19 +87,6 @@ void flash_clear_status_flags(void)
 	flash_clear_eop_flag();
 }
 
-/*---------------------------------------------------------------------------*/
-/** @brief Unlock the Option Byte Access
-
-This enables write access to the option bytes. It is locked by default on
-reset.
-*/
-
-void flash_unlock_option_bytes(void)
-{
-	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY1;
-	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY2;
-}
-
 /*---------------------------------------------------------------------------*/
 /** @brief Lock the Option Byte Access
 
diff --git a/lib/stm32/common/flash_common_l01.c b/lib/stm32/common/flash_common_l01.c
index 7ca1f48d..9eceb45f 100644
--- a/lib/stm32/common/flash_common_l01.c
+++ b/lib/stm32/common/flash_common_l01.c
@@ -64,18 +64,6 @@ void flash_lock_progmem(void)
 	FLASH_PECR |= FLASH_PECR_PRGLOCK;
 }
 
-/**
- * Unlock option bytes.
- * Writes the magic sequence to unlock the option bytes,
- * you must have already unlocked access to this register!
- * @sa flash_unlock_pecr
- */
-void flash_unlock_option_bytes(void)
-{
-	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY1;
-	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY2;
-}
-
 void flash_lock_option_bytes(void)
 {
 	FLASH_PECR |= FLASH_PECR_OPTLOCK;
diff --git a/lib/stm32/f7/flash.c b/lib/stm32/f7/flash.c
index 0dcf388b..a81815a9 100644
--- a/lib/stm32/f7/flash.c
+++ b/lib/stm32/f7/flash.c
@@ -82,19 +82,6 @@ void flash_wait_for_last_operation(void)
 	while ((FLASH_SR & FLASH_SR_BSY) == FLASH_SR_BSY);
 }
 
-/*---------------------------------------------------------------------------*/
-/** @brief Unlock the Option Byte Access
-
-This enables write access to the option bytes. It is locked by default on
-reset.
-*/
-
-void flash_unlock_option_bytes(void)
-{
-	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY1;
-	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY2;
-}
-
 /*---------------------------------------------------------------------------*/
 /** @brief Lock the Option Byte Access
 
diff --git a/lib/stm32/l4/flash.c b/lib/stm32/l4/flash.c
index fd3665aa..c3ec1f5e 100644
--- a/lib/stm32/l4/flash.c
+++ b/lib/stm32/l4/flash.c
@@ -92,16 +92,6 @@ void flash_clear_status_flags(void)
 	flash_clear_eop_flag();
 }
 
-/** @brief Unlock the Option Byte Access
- * This enables write access to the option bytes. It is locked by default on
- * reset.
- */
-void flash_unlock_option_bytes(void)
-{
-	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY1;
-	FLASH_OPTKEYR = FLASH_OPTKEYR_KEY2;
-}
-
 /** @brief Lock the Option Byte Access
  * This disables write access to the option bytes. It is locked by default on
  * reset.