diff --git a/source/arm9/crypto.c b/source/arm9/crypto.c
index daf87de..353eccb 100644
--- a/source/arm9/crypto.c
+++ b/source/arm9/crypto.c
@@ -5,8 +5,10 @@
  *  profi200
  */
 
+#include <assert.h>
 #include <string.h>
 #include "types.h"
+#include "mem_map.h"
 #include "arm9/crypto.h"
 #include "arm9/interrupt.h"
 #include "arm9/ndma.h"
@@ -133,6 +135,10 @@
 
 void AES_crypt(AES_ctx *restrict ctx, const u32 *restrict in, u32 *restrict out, u32 size)
 {
+	// DMA can't reach TCMs
+	assert(((u32)in >= ITCM_BOOT9_MIRROR + ITCM_SIZE) && (((u32)in < DTCM_BASE) || ((u32)in >= DTCM_BASE + DTCM_SIZE)));
+	assert(((u32)out >= ITCM_BOOT9_MIRROR + ITCM_SIZE) && (((u32)out < DTCM_BASE) || ((u32)out >= DTCM_BASE + DTCM_SIZE)));
+
 	// Align to 16 bytes.
 	size = (size + 0xFu) & ~0xFu;
 
diff --git a/source/arm9/ndma.c b/source/arm9/ndma.c
index 74edc74..2e22788 100644
--- a/source/arm9/ndma.c
+++ b/source/arm9/ndma.c
@@ -3,7 +3,9 @@
  * profi200
  */
 
+#include <assert.h>
 #include "types.h"
+#include "mem_map.h"
 #include "arm9/ndma.h"
 #include "arm9/interrupt.h"
 
@@ -11,6 +13,9 @@
 
 void NDMA_copy(u32 *dest, const u32 *source, u32 num)
 {
+	assert(((u32)dest >= ITCM_BOOT9_MIRROR + ITCM_SIZE) && (((u32)dest < DTCM_BASE) || ((u32)dest >= DTCM_BASE + DTCM_SIZE)));
+	assert(((u32)source >= ITCM_BOOT9_MIRROR + ITCM_SIZE) && (((u32)source < DTCM_BASE) || ((u32)source >= DTCM_BASE + DTCM_SIZE)));
+
 	REG_NDMA7_SRC_ADDR = (u32)source;
 	REG_NDMA7_DST_ADDR = (u32)dest;
 	REG_NDMA7_WRITE_CNT = num;
@@ -26,6 +31,8 @@
 
 void NDMA_fill(u32 *dest, u32 value, u32 num)
 {
+	assert(((u32)dest >= ITCM_BOOT9_MIRROR + ITCM_SIZE) && (((u32)dest < DTCM_BASE) || ((u32)dest >= DTCM_BASE + DTCM_SIZE)));
+
 	REG_NDMA7_DST_ADDR = (u32)dest;
 	REG_NDMA7_WRITE_CNT = num;
 	REG_NDMA7_BLOCK_CNT = NDMA_BLOCK_SYS_FREQ;