diff --git a/arch/arm/src/armv7-m/mpu.h b/arch/arm/src/armv7-m/mpu.h
index 1418ca97708..2e3770ffb67 100644
--- a/arch/arm/src/armv7-m/mpu.h
+++ b/arch/arm/src/armv7-m/mpu.h
@@ -86,7 +86,7 @@
 
 /* MPU Region Number Register Bit Definitions */
 
-#ifdef CONFIG_ARM_MPU_NREGIONS <= 8
+#if CONFIG_ARM_MPU_NREGIONS <= 8
 #  define MPU_RNR_MASK            (0x00000007)
 #elif CONFIG_ARM_MPU_NREGIONS <= 16
 #  define MPU_RNR_MASK            (0x0000000f)
diff --git a/arch/arm/src/armv7-r/mpu.h b/arch/arm/src/armv7-r/mpu.h
index 703883988fd..4cd962b9f73 100644
--- a/arch/arm/src/armv7-r/mpu.h
+++ b/arch/arm/src/armv7-r/mpu.h
@@ -106,7 +106,7 @@
 
 /* MPU Region Number Register */
 
-#ifdef CONFIG_ARM_MPU_NREGIONS <= 8
+#if CONFIG_ARM_MPU_NREGIONS <= 8
 #  define MPU_RGNR_MASK          (0x00000007)
 #elif CONFIG_ARM_MPU_NREGIONS <= 16
 #  define MPU_RGNR_MASK          (0x0000000f)