diff --git a/source/Mockingboard.cpp b/source/Mockingboard.cpp
index 9bf96736..b4044263 100644
--- a/source/Mockingboard.cpp
+++ b/source/Mockingboard.cpp
@@ -445,7 +445,7 @@ static void SY6522_Write(BYTE nDevice, BYTE nReg, BYTE nValue)
 			pMB->sy6522.TIMER2_COUNTER.w = pMB->sy6522.TIMER2_LATCH.w;
 
 			StartTimer2(pMB);
-			CpuAdjustIrqCheck(pMB->sy6522.TIMER1_LATCH.w);	// Sync IRQ check timeout with 6522 counter underflow - GH#608
+			CpuAdjustIrqCheck(pMB->sy6522.TIMER2_LATCH.w);	// Sync IRQ check timeout with 6522 counter underflow - GH#608
 			break;
 		case 0x0a:	// SERIAL_SHIFT
 			break;