diff --git a/cpu/cortexm_common/vectors_cortexm.c b/cpu/cortexm_common/vectors_cortexm.c
index 5f39c5c552..4a751d4bcf 100644
--- a/cpu/cortexm_common/vectors_cortexm.c
+++ b/cpu/cortexm_common/vectors_cortexm.c
@@ -140,10 +140,6 @@ void reset_handler_default(void)
     }
 #endif /* CPU_HAS_BACKUP_RAM */
 
-#if defined(MODULE_MPU_STACK_GUARD) || defined(MODULE_MPU_NOEXEC_RAM)
-    mpu_enable();
-#endif
-
 #ifdef MODULE_MPU_NOEXEC_RAM
     /* Mark the RAM non executable. This is a protection mechanism which
      * makes exploitation of buffer overflows significantly harder.
@@ -169,6 +165,10 @@ void reset_handler_default(void)
     }
 #endif
 
+#if defined(MODULE_MPU_STACK_GUARD) || defined(MODULE_MPU_NOEXEC_RAM)
+    mpu_enable();
+#endif
+
     post_startup();
 
     /* initialize the board (which also initiates CPU initialization) */