diff --git a/src/gbemu/cpu.c b/src/gbemu/cpu.c
index b49831b..9a6db48 100644
--- a/src/gbemu/cpu.c
+++ b/src/gbemu/cpu.c
@@ -99,30 +99,30 @@ void lr35902_init(struct lr35902_state *cpu,
 	cpu->metrics.mem_writes = 0;
 }
 
-/* The shortest number of cycles each instruction may take. */
-static const unsigned int op_cycles[256] = {
-	/* 0x0_ */ 4, 12, 8, 8, 4, 4, 8, 4, 20, 8, 8, 8, 4, 4, 8, 4,
-	/* 0x1_ */ 4, 12, 8, 8, 4, 4, 8, 4, 12, 8, 8, 8, 4, 4, 8, 4,
-	/* 0x2_ */ 8, 12, 8, 8, 4, 4, 8, 4, 8, 8, 8, 8, 4, 4, 8, 4,
-	/* 0x3_ */ 8, 12, 8, 8, 12, 12, 12, 4, 8, 8, 8, 8, 4, 4, 8, 4,
-	/* 0x4_ */ 4, 4, 4, 4, 4, 4, 8, 4, 4, 4, 4, 4, 4, 4, 8, 4,
-	/* 0x5_ */ 4, 4, 4, 4, 4, 4, 8, 4, 4, 4, 4, 4, 4, 4, 8, 4,
-	/* 0x6_ */ 4, 4, 4, 4, 4, 4, 8, 4, 4, 4, 4, 4, 4, 4, 8, 4,
-	/* 0x7_ */ 8, 8, 8, 8, 8, 8, 4, 8, 4, 4, 4, 4, 4, 4, 8, 4,
+static const unsigned int op_extra_cycles[256] = {
+	/* 0x0_ */ 0, 2, 1, 1, 0, 0, 1, 0, 4, 1, 1, 1, 0, 0, 1, 0,
+	/* 0x1_ */ 0, 2, 1, 1, 0, 0, 1, 0, 2, 1, 1, 1, 0, 0, 1, 0,
+	/* 0x2_ */ 1, 2, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0,
+	/* 0x3_ */ 1, 2, 1, 1, 2, 2, 2, 0, 1, 1, 1, 1, 0, 0, 1, 0,
+	/* 0x4_ */ 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+	/* 0x5_ */ 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+	/* 0x6_ */ 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+	/* 0x7_ */ 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0,
 
 	//FIXME
-	/* 0x0_ */ 4, 12, 8, 8, 4, 4, 8, 4, 20, 8, 8, 8, 4, 4, 8, 4,
-	/* 0x1_ */ 4, 12, 8, 8, 4, 4, 8, 4, 12, 8, 8, 8, 4, 4, 8, 4,
-	/* 0x2_ */ 8, 12, 8, 8, 4, 4, 8, 4, 8, 8, 8, 8, 4, 4, 8, 4,
-	/* 0x3_ */ 8, 12, 8, 8, 12, 12, 12, 4, 8, 8, 8, 8, 4, 4, 8, 4,
-	/* 0x4_ */ 4, 4, 4, 4, 4, 4, 8, 4, 4, 4, 4, 4, 4, 4, 8, 4,
-	/* 0x5_ */ 4, 4, 4, 4, 4, 4, 8, 4, 4, 4, 4, 4, 4, 4, 8, 4,
-	/* 0x6_ */ 4, 4, 4, 4, 4, 4, 8, 4, 4, 4, 4, 4, 4, 4, 8, 4,
-	/* 0x7_ */ 8, 8, 8, 8, 8, 8, 4, 8, 4, 4, 4, 4, 4, 4, 8, 4,
+	/* 0x0_ */ 0, 2, 1, 1, 0, 0, 1, 0, 4, 1, 1, 1, 0, 0, 1, 0,
+	/* 0x1_ */ 0, 2, 1, 1, 0, 0, 1, 0, 2, 1, 1, 1, 0, 0, 1, 0,
+	/* 0x2_ */ 1, 2, 1, 1, 0, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0,
+	/* 0x3_ */ 1, 2, 1, 1, 2, 2, 2, 0, 1, 1, 1, 1, 0, 0, 1, 0,
+	/* 0x4_ */ 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+	/* 0x5_ */ 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+	/* 0x6_ */ 0, 0, 0, 0, 0, 3, 1, 3, 3, 3, 3, 3, 3, 3, 1, 3,
+	/* 0x7_ */ 1, 1, 1, 1, 1, 1, 3, 1, 3, 3, 3, 3, 3, 3, 1, 3,
 
 };
 
-static const unsigned int cb_op_cycles[256] = { 0 };
+
+static const unsigned int cb_extra_cycles[256] = { 0 };
 
 /* TODO: optimize macros with temp variables so mem_read() doesn't expand multiple times */
 #define INC_8(cpu, reg)							\
@@ -318,7 +318,6 @@ static const unsigned int cb_op_cycles[256] = { 0 };
 void lr35902_cycle(struct lr35902_state *cpu)
 {
 	uint8_t inst;
-	unsigned int cycles;
 	uint8_t val;
 	uint16_t val_16;
 	uint8_t *reg = NULL;
@@ -334,7 +333,7 @@ void lr35902_cycle(struct lr35902_state *cpu)
 	}
 
 	inst = cpu->mem_read(cpu, cpu->pc++);
-	cycles = op_cycles[inst];
+	cpu->stall_cycles = op_extra_cycles[inst];
 
 	switch (inst) {
 	case 0x00: /* NOP */
@@ -999,7 +998,7 @@ void lr35902_cycle(struct lr35902_state *cpu)
 	case 0xca:
 	case 0xcb:
 		inst = cpu->mem_read(cpu, cpu->pc++);
-		cycles = cb_op_cycles[inst];
+		cpu->stall_cycles = cb_extra_cycles[inst];
 		switch (inst) {
 		case 0x00:
 		case 0x01:
@@ -1469,6 +1468,4 @@ void lr35902_cycle(struct lr35902_state *cpu)
 		RST(cpu, 0x38);
 		break;
 	}
-
-	cpu->stall_cycles = cycles - 1;
 }