diff --git a/boards/microbit/include/periph_conf.h b/boards/microbit/include/periph_conf.h
index 7c6f050d78..4ee73ee735 100644
--- a/boards/microbit/include/periph_conf.h
+++ b/boards/microbit/include/periph_conf.h
@@ -102,7 +102,8 @@ static const i2c_conf_t i2c_config[] = {
         .dev     = NRF_TWI0,
         .pin_scl = 0,
         .pin_sda = 30,
-        .ppi     = 0
+        .ppi     = 0,
+        .speed   = I2C_SPEED_NORMAL,
     }
 };