diff --git a/src/gb/gb.c b/src/gb/gb.c
index 9d85b02e2..bd2726e70 100644
--- a/src/gb/gb.c
+++ b/src/gb/gb.c
@@ -425,6 +425,7 @@ void GBReset(struct LR35902Core* cpu) {
 		cpu->pc = 0x100;
 	}
 
+	gb->cpuBlocked = false;
 	gb->eiPending = INT_MAX;
 	gb->doubleSpeed = 0;
 
@@ -546,7 +547,11 @@ void GBProcessEvents(struct LR35902Core* cpu) {
 			}
 		}
 
-		cpu->nextEvent = mTimingTick(&gb->timing, cycles);
+		nextEvent = cycles;
+		do {
+			nextEvent = mTimingTick(&gb->timing, nextEvent);
+		} while (gb->cpuBlocked);
+		cpu->nextEvent = nextEvent;
 
 		if (cpu->halted) {
 			cpu->cycles = cpu->nextEvent;
diff --git a/src/gb/gb.h b/src/gb/gb.h
index 584ce4bba..2ec4a3234 100644
--- a/src/gb/gb.h
+++ b/src/gb/gb.h
@@ -78,6 +78,7 @@ struct GB {
 	struct mCoreCallbacks* coreCallbacks;
 	struct mAVStream* stream;
 
+	bool cpuBlocked;
 	int32_t eiPending;
 	unsigned doubleSpeed;
 };
diff --git a/src/gb/memory.c b/src/gb/memory.c
index ebcd107b5..1fb24f1cf 100644
--- a/src/gb/memory.c
+++ b/src/gb/memory.c
@@ -381,6 +381,7 @@ void GBMemoryWriteHDMA5(struct GB* gb, uint8_t value) {
 	gb->memory.isHdma = value & 0x80;
 	if ((!wasHdma && !gb->memory.isHdma) || gb->video.mode == 0) {
 		gb->memory.hdmaRemaining = ((value & 0x7F) + 1) * 0x10;
+		gb->cpuBlocked = true;
 		mTimingSchedule(&gb->timing, &gb->memory.hdmaEvent, 0);
 		gb->cpu->nextEvent = gb->cpu->cycles;
 	}
@@ -404,14 +405,17 @@ void _GBMemoryDMAService(struct mTiming* timing, void* context, uint32_t cyclesL
 
 void _GBMemoryHDMAService(struct mTiming* timing, void* context, uint32_t cyclesLate) {
 	struct GB* gb = context;
+	gb->cpuBlocked = true;
 	uint8_t b = gb->cpu->memory.load8(gb->cpu, gb->memory.hdmaSource);
 	gb->cpu->memory.store8(gb->cpu, gb->memory.hdmaDest, b);
 	++gb->memory.hdmaSource;
 	++gb->memory.hdmaDest;
 	--gb->memory.hdmaRemaining;
 	if (gb->memory.hdmaRemaining) {
+		mTimingDeschedule(timing, &gb->memory.hdmaEvent);
 		mTimingSchedule(timing, &gb->memory.hdmaEvent, 2 - cyclesLate);
 	} else {
+		gb->cpuBlocked = false;
 		gb->memory.io[REG_HDMA1] = gb->memory.hdmaSource >> 8;
 		gb->memory.io[REG_HDMA2] = gb->memory.hdmaSource;
 		gb->memory.io[REG_HDMA3] = gb->memory.hdmaDest >> 8;
@@ -425,7 +429,6 @@ void _GBMemoryHDMAService(struct mTiming* timing, void* context, uint32_t cycles
 			gb->memory.io[REG_HDMA5] = 0xFF;
 		}
 	}
-	gb->cpu->cycles += 2;
 }
 
 struct OAMBlock {
diff --git a/src/gb/video.c b/src/gb/video.c
index b54d96d1e..ef8bb95c5 100644
--- a/src/gb/video.c
+++ b/src/gb/video.c
@@ -206,6 +206,7 @@ void _endMode3(struct mTiming* timing, void* context, uint32_t cyclesLate) {
 	}
 	if (video->ly < GB_VIDEO_VERTICAL_PIXELS && video->p->memory.isHdma && video->p->memory.io[REG_HDMA5] != 0xFF) {
 		video->p->memory.hdmaRemaining = 0x10;
+		mTimingDeschedule(timing, &video->p->memory.hdmaEvent);
 		mTimingSchedule(timing, &video->p->memory.hdmaEvent, 0);
 	}
 	video->mode = 0;