diff --git a/firmware/config/boards/f407-discovery/board.mk b/firmware/config/boards/f407-discovery/board.mk
index ed7bde1f90..5fe386dad2 100644
--- a/firmware/config/boards/f407-discovery/board.mk
+++ b/firmware/config/boards/f407-discovery/board.mk
@@ -6,6 +6,7 @@ DDEFS += -DSTM32F407xx
 
 # We are running on Frankenso hardware!
 DDEFS += -DHW_FRANKENSO=1
+DDEFS += -DSTM32_I2C_USE_I2C3=TRUE
 
 ifndef IS_RE_BOOTLOADER
 DDEFS += -DHAL_USE_EEPROM=TRUE
diff --git a/firmware/hw_layer/ports/stm32/mcuconf_common_f4_f7.h b/firmware/hw_layer/ports/stm32/mcuconf_common_f4_f7.h
index cc21adcb33..8d4465de97 100644
--- a/firmware/hw_layer/ports/stm32/mcuconf_common_f4_f7.h
+++ b/firmware/hw_layer/ports/stm32/mcuconf_common_f4_f7.h
@@ -137,11 +137,25 @@
 /*
  * I2C driver system settings.
  */
+#ifndef STM32_I2C_USE_I2C1
 #define STM32_I2C_USE_I2C1                  FALSE
-/* PB10/PB11 like some Hellen likes */
+#endif
+
+#ifndef STM32_I2C_USE_I2C2
+/* PB10/PB11 like some Hellen likes AF4 */
 #define STM32_I2C_USE_I2C2                  TRUE
+#endif
+
+#ifndef STM32_I2C_USE_I2C3
+// PC9 I2C3_SDA AF4
+// PA8 I2C3_SCL AF4
 #define STM32_I2C_USE_I2C3                  FALSE
+#endif
+
+#ifndef STM32_I2C_USE_I2C4
 #define STM32_I2C_USE_I2C4                  FALSE
+#endif
+
 #define STM32_I2C_BUSY_TIMEOUT              50
 #define STM32_I2C_I2C1_RX_DMA_STREAM        STM32_DMA_STREAM_ID(1, 0)
 #define STM32_I2C_I2C1_TX_DMA_STREAM        STM32_DMA_STREAM_ID(1, 6)