diff --git a/source/arm9/ndma.c b/source/arm9/ndma.c
index 8262b3c..db3051a 100644
--- a/source/arm9/ndma.c
+++ b/source/arm9/ndma.c
@@ -13,6 +13,8 @@
 
 void NDMA_init(void)
 {
+	u32 oldState = enterCriticalSection();
+
 	for(u32 i = 0; i < 8; i++)
 	{
 		REG_NDMA_CNT(i) = (REG_NDMA_CNT(i)<<1)>>1;
@@ -22,6 +24,8 @@
 
 	REG_IRQ_IE |= ((1u<<IRQ_DMAC_1_0) | (1u<<IRQ_DMAC_1_1) | (1u<<IRQ_DMAC_1_2) | (1u<<IRQ_DMAC_1_3) |
 					(1u<<IRQ_DMAC_1_4) | (1u<<IRQ_DMAC_1_5) | (1u<<IRQ_DMAC_1_6) | (1u<<IRQ_DMAC_1_7));
+
+	leaveCriticalSection(oldState);
 }
 
 void NDMA_copy(u32 *dest, const u32 *source, u32 num)
diff --git a/source/arm9/pxi.c b/source/arm9/pxi.c
index 1158e8d..9357e52 100644
--- a/source/arm9/pxi.c
+++ b/source/arm9/pxi.c
@@ -6,6 +6,8 @@
 
 void PXI_init(void)
 {
+	u32 oldState = enterCriticalSection();
+
 	REG_PXI_SYNC9 = PXI_IRQ_ENABLE;
 	REG_PXI_CNT9 = PXI_FLUSH_SEND_FIFO | PXI_EMPTY_FULL_ERROR | PXI_ENABLE_SEND_RECV_FIFO;
 
@@ -13,6 +15,8 @@
 	while((REG_PXI_SYNC9 & 0xFFu) != 11u);
 
 	REG_IRQ_IE |= ((1u<<IRQ_PXI_SYNC) | (1u<<IRQ_PXI_NOT_FULL) | (1u<<IRQ_PXI_NOT_EMPTY));
+
+	leaveCriticalSection(oldState);
 }
 
 void PXI_sendWord(u32 val)
diff --git a/source/arm9/timer.c b/source/arm9/timer.c
index 082783d..edc3e17 100644
--- a/source/arm9/timer.c
+++ b/source/arm9/timer.c
@@ -6,12 +6,16 @@
 
 void TIMER_init(void)
 {
+	u32 oldState = enterCriticalSection();
+
 	for(u32 i = 0; i < 4; i++)
 	{
 		REG_TIMER_CNT(i) = 0;
 	}
 
 	REG_IRQ_IE |= ((1u<<IRQ_TIMER_0) | (1u<<IRQ_TIMER_1) | (1u<<IRQ_TIMER_2) | (1u<<IRQ_TIMER_3));
+
+	leaveCriticalSection(oldState);
 }
 
 void TIMER_start(Timer timer, TimerPrescaler prescaler, u16 ticks, void (*irqHandler)(void))