diff --git a/boards/nucleo-l1/include/periph_conf.h b/boards/nucleo-l1/include/periph_conf.h
index 92db33d20c38918b26f9b75ecc8cb6fdbaee0c5d..f546df389422eab52becf2304e466c304790202b 100644
--- a/boards/nucleo-l1/include/periph_conf.h
+++ b/boards/nucleo-l1/include/periph_conf.h
@@ -254,9 +254,9 @@ static const timer_conf_t timer_config[] = {
 
 static const i2c_conf_t i2c_config[] = {
     /* device, port, scl-, sda-pin-number, I2C-AF, ER-IRQn, EV-IRQn */
-    {I2C1, GPIO_PIN(PORT_B,  8), GPIO_PIN(PORT_B,  9),
+    {I2C1, GPIO_PIN(PORT_B,  8), GPIO_PIN(PORT_B,  9), GPIO_OD_PU,
      GPIO_AF4, I2C1_ER_IRQn, I2C1_EV_IRQn},
-    {I2C2, GPIO_PIN(PORT_B, 10), GPIO_PIN(PORT_B, 11),
+    {I2C2, GPIO_PIN(PORT_B, 10), GPIO_PIN(PORT_B, 11), GPIO_OD_PU,
      GPIO_AF4, I2C2_ER_IRQn, I2C2_EV_IRQn},
 };