diff --git a/include/configs/ethernut5.h b/include/configs/ethernut5.h
index 807c696..c327bbb 100644
--- a/include/configs/ethernut5.h
+++ b/include/configs/ethernut5.h
@@ -59,9 +59,6 @@
 #define CFG_SYS_I2C_RTC_ADDR		0x51
 #endif
 
-/* I2C */
-#define CFG_SYS_MAX_I2C_BUS	1
-
 #define I2C_SOFT_DECLARATIONS
 
 #define GPIO_I2C_SCL		AT91_PIO_PORTA, 24
diff --git a/include/i2c.h b/include/i2c.h
index b6727bb..282f3cd 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -933,20 +933,6 @@
 unsigned int i2c_get_bus_speed(void);
 #endif /* CONFIG_SYS_I2C_LEGACY */
 
-/*
- * only for backwardcompatibility, should go away if we switched
- * completely to new multibus support.
- */
-#if CONFIG_IS_ENABLED(SYS_I2C_LEGACY)
-# if !defined(CFG_SYS_MAX_I2C_BUS)
-#  define CFG_SYS_MAX_I2C_BUS		2
-# endif
-# define I2C_MULTI_BUS				1
-#else
-# define CFG_SYS_MAX_I2C_BUS		1
-# define I2C_MULTI_BUS				0
-#endif
-
 /**
  * Find the I2C bus number by given a FDT I2C node.
  *