diff --git a/Inc/stm32l1xx_ll_cortex.h b/Inc/stm32l1xx_ll_cortex.h
index f210016..3fec1a3 100644
--- a/Inc/stm32l1xx_ll_cortex.h
+++ b/Inc/stm32l1xx_ll_cortex.h
@@ -586,7 +586,7 @@
   /* Set base address */
   WRITE_REG(MPU->RBAR, (Address & 0xFFFFFFE0U));
   /* Configure MPU */
-  WRITE_REG(MPU->RASR, (MPU_RASR_ENABLE_Msk | Attributes | SubRegionDisable << MPU_RASR_SRD_Pos));
+  WRITE_REG(MPU->RASR, (MPU_RASR_ENABLE_Msk | Attributes | (SubRegionDisable << MPU_RASR_SRD_Pos)));
 }
 
 /**