diff --git a/include/spi.h b/include/spi.h
index 4664bbd4814..bd58fb86b83 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -127,7 +127,7 @@ static inline int spi_configure(struct device *dev,
  *
  * @return DEV_OK if successful, another DEV_* code otherwise.
  */
-inline int spi_slave_select(struct device *dev, uint32_t slave)
+static inline int spi_slave_select(struct device *dev, uint32_t slave)
 {
 	struct spi_driver_api *api = (struct spi_driver_api *)dev->driver_api;