diff --git a/cpu/kinetis_common/i2c.c b/cpu/kinetis_common/i2c.c
index 901c314680..6f6d9a8b6a 100644
--- a/cpu/kinetis_common/i2c.c
+++ b/cpu/kinetis_common/i2c.c
@@ -154,14 +154,6 @@ int i2c_init_master(i2c_t dev, i2c_speed_t speed)
     return 0;
 }
 
-int i2c_init_slave(i2c_t dev, uint8_t address)
-{
-    /* TODO: implement slave mode */
-    (void) dev;
-    (void) address;
-    return -1;
-}
-
 /*
  * Check for bus master arbitration lost.
  * Arbitration is lost in the following circumstances: