diff --git a/boards/common/stm32f103c8/include/periph_conf.h b/boards/common/stm32f103c8/include/periph_conf.h
index 2f56a63677..297948a65b 100644
--- a/boards/common/stm32f103c8/include/periph_conf.h
+++ b/boards/common/stm32f103c8/include/periph_conf.h
@@ -155,7 +155,8 @@ static const uart_conf_t uart_config[] = {
 /** @} */
 
 /**
- * @name I2C configuration
+ * @name    I2C configuration
+ * @note    This board may require external pullup resistors for i2c operation.
  * @{
  */
 static const i2c_conf_t i2c_config[] = {
diff --git a/boards/nucleo-f103rb/include/periph_conf.h b/boards/nucleo-f103rb/include/periph_conf.h
index 3863bfbed5..d48875edca 100644
--- a/boards/nucleo-f103rb/include/periph_conf.h
+++ b/boards/nucleo-f103rb/include/periph_conf.h
@@ -144,7 +144,8 @@ static const uart_conf_t uart_config[] = {
 /** @} */
 
 /**
- * @name I2C configuration
+ * @name    I2C configuration
+ * @note    This board may require external pullup resistors for i2c operation.
  * @{
  */
 static const i2c_conf_t i2c_config[] = {
diff --git a/cpu/stm32_common/periph/i2c_2.c b/cpu/stm32_common/periph/i2c_2.c
index f89ea229db..39ab925982 100644
--- a/cpu/stm32_common/periph/i2c_2.c
+++ b/cpu/stm32_common/periph/i2c_2.c
@@ -109,6 +109,14 @@ void i2c_init(i2c_t dev)
     gpio_init(i2c_config[dev].scl_pin, GPIO_OD_PU);
     gpio_init(i2c_config[dev].sda_pin, GPIO_OD_PU);
 #ifdef CPU_FAM_STM32F1
+    /* This is needed in case the remapped pins are used */
+    if (i2c_config[dev].scl_pin == GPIO_PIN(PORT_B, 8) ||
+        i2c_config[dev].sda_pin == GPIO_PIN(PORT_B, 9)) {
+        /* The remapping periph clock must first be enabled */
+        RCC->APB2ENR |= RCC_APB2ENR_AFIOEN;
+        /* Then the remap can occur */
+        AFIO->MAPR |= AFIO_MAPR_I2C1_REMAP;
+    }
     gpio_init_af(i2c_config[dev].scl_pin, GPIO_AF_OUT_OD);
     gpio_init_af(i2c_config[dev].sda_pin, GPIO_AF_OUT_OD);
 #else