diff --git a/cpu/stm32_common/periph/i2c_1.c b/cpu/stm32_common/periph/i2c_1.c
index 2422539a8f..61d8347155 100644
--- a/cpu/stm32_common/periph/i2c_1.c
+++ b/cpu/stm32_common/periph/i2c_1.c
@@ -37,6 +37,7 @@
 
 #include "cpu.h"
 #include "mutex.h"
+#include "byteorder.h"
 
 #include "cpu_conf_stm32_common.h"
 
@@ -169,6 +170,10 @@ int i2c_write_regs(i2c_t dev, uint16_t addr, uint16_t reg,
     if (i2c->ISR & I2C_ISR_BUSY) {
         return -EAGAIN;
     }
+    /* Handle endianess of register if 16 bit */
+    if (flags & I2C_REG16) {
+        reg = htons(reg); /* Make sure register is in big-endian on I2C bus */
+    }
     /* First set ADDR and register with no stop */
     /* No RELOAD should be set so repeated start is valid */
     int ret = _write(i2c, addr, &reg, (flags & I2C_REG16) ? 2 : 1,