diff --git a/arch/arm/src/kinetis/Make.defs b/arch/arm/src/kinetis/Make.defs
index 6ee494c6526..8ec4063b6d3 100644
--- a/arch/arm/src/kinetis/Make.defs
+++ b/arch/arm/src/kinetis/Make.defs
@@ -116,6 +116,7 @@ CHIP_CSRCS += kinetis_lowputc.c kinetis_pin.c kinetis_pingpio.c
 CHIP_CSRCS += kinetis_serialinit.c kinetis_serial.c
 CHIP_CSRCS += kinetis_start.c kinetis_uid.c kinetis_wdog.c
 CHIP_CSRCS += kinetis_cfmconfig.c
+CHIP_CSRCS += kinetis_mpuinit.c
 
 # Configuration-dependent Kinetis files
 
@@ -124,7 +125,7 @@ CHIP_CSRCS += kinetis_timerisr.c
 endif
 
 ifeq ($(CONFIG_BUILD_PROTECTED),y)
-CHIP_CSRCS += kinetis_userspace.c kinetis_mpuinit.c
+CHIP_CSRCS += kinetis_userspace.c
 endif
 
 ifeq ($(CONFIG_KINETIS_GPIOIRQ),y)
diff --git a/arch/arm/src/kinetis/kinetis_mpuinit.c b/arch/arm/src/kinetis/kinetis_mpuinit.c
index 6c41f85bf4f..9618b5a071d 100644
--- a/arch/arm/src/kinetis/kinetis_mpuinit.c
+++ b/arch/arm/src/kinetis/kinetis_mpuinit.c
@@ -45,6 +45,7 @@
 
 #include "mpu.h"
 #include "kinetis_mpuinit.h"
+#include "chip/kinetis_mpu.h"
 
 #if defined(CONFIG_BUILD_PROTECTED) && defined(CONFIG_ARM_MPU)
 
@@ -120,5 +121,24 @@ void kinetis_mpu_uheap(uintptr_t start, size_t size)
   mpu_user_intsram(start, size);
 }
 
+#elif defined(KINETIS_MPU)
+
+/****************************************************************************
+ * Name: kinetis_mpudisable
+ *
+ * Description:
+ *   Configure the MPU to permit All buss masters access to all resources.
+ *
+ ****************************************************************************/
+
+void kinetis_mpudisable(void)
+{
+  uint32_t regval;
+
+  regval = getreg32(KINETIS_MPU_CESR);
+  regval &= ~MPU_CESR_VLD;
+  putreg32(regval, KINETIS_MPU_CESR);
+}
+
 #endif /* CONFIG_BUILD_PROTECTED && CONFIG_ARM_MPU */
 
diff --git a/arch/arm/src/kinetis/kinetis_mpuinit.h b/arch/arm/src/kinetis/kinetis_mpuinit.h
index 3327176841b..91abf8e122d 100644
--- a/arch/arm/src/kinetis/kinetis_mpuinit.h
+++ b/arch/arm/src/kinetis/kinetis_mpuinit.h
@@ -61,6 +61,18 @@ void kinetis_mpuinitialize(void);
 #  define kinetis_mpuinitialize()
 #endif
 
+/****************************************************************************
+ * Name: kinetis_mpudisable
+ *
+ * Description:
+ *   Configure the MPU to permit All buss masters access to all resources.
+ *
+ ****************************************************************************/
+
+#if !defined(CONFIG_BUILD_PROTECTED) && defined(KINETIS_MPU)
+void kinetis_mpudisable(void);
+#endif
+
 /****************************************************************************
  * Name: kinetis_mpu_uheap
  *
diff --git a/arch/arm/src/kinetis/kinetis_start.c b/arch/arm/src/kinetis/kinetis_start.c
index f7445c5cde0..d139d9533a8 100644
--- a/arch/arm/src/kinetis/kinetis_start.c
+++ b/arch/arm/src/kinetis/kinetis_start.c
@@ -341,6 +341,12 @@ void __start(void)
 
 #ifdef CONFIG_BUILD_PROTECTED
   kinetis_userspace();
+#else
+#  ifdef KINETIS_MPU
+  /* Disable the MPU so that all master may access all buses */
+
+  kinetis_mpudisable();
+#  endif
 #endif
 
   /* Initialize other on-board resources */