diff --git a/src/burn/drv/sega/d_sys16a.cpp b/src/burn/drv/sega/d_sys16a.cpp
index bbc37be68..d82c9b14a 100644
--- a/src/burn/drv/sega/d_sys16a.cpp
+++ b/src/burn/drv/sega/d_sys16a.cpp
@@ -2550,6 +2550,7 @@ static INT32 AliensynjoInit()
 			memcpy(System16Sprites + 0x50000, pTemp + 0x30000, 0x10000);
 			memcpy(System16Sprites + 0x60000, pTemp + 0x50000, 0x10000);
 			memcpy(System16Sprites + 0x70000, pTemp + 0x70000, 0x10000);
+			AlienSyndrome = true;
 		} else {
 			nRet = 1;
 		}
@@ -2576,6 +2577,7 @@ static INT32 Aliensyn5Init()
 			memcpy(System16Sprites + 0x50000, pTemp + 0x30000, 0x10000);
 			memcpy(System16Sprites + 0x60000, pTemp + 0x50000, 0x10000);
 			memcpy(System16Sprites + 0x70000, pTemp + 0x70000, 0x10000);
+			AlienSyndrome = true;
 		} else {
 			nRet = 1;
 		}
diff --git a/src/burn/drv/sega/d_sys16b.cpp b/src/burn/drv/sega/d_sys16b.cpp
index 6d11038e2..9327bbb53 100644
--- a/src/burn/drv/sega/d_sys16b.cpp
+++ b/src/burn/drv/sega/d_sys16b.cpp
@@ -6455,6 +6455,7 @@ static INT32 AliensynInit()
 		SekMapHandler(1, 0xc00006, 0xc00007, SM_WRITE);
 		SekSetWriteByteHandler(1, AliensynWriteByte);
 		SekClose();
+		AlienSyndrome = true;
 	}
 	
 	return nRet;
@@ -6469,6 +6470,7 @@ static INT32 Aliensyn3Init()
 		SekMapHandler(1, 0xc00006, 0xc00007, SM_WRITE);
 		SekSetWriteByteHandler(1, AliensynWriteByte);
 		SekClose();
+		AlienSyndrome = true;
 	}
 	
 	return nRet;
diff --git a/src/burn/drv/sega/sys16.h b/src/burn/drv/sega/sys16.h
index 06e8de30d..a1666b64d 100644
--- a/src/burn/drv/sega/sys16.h
+++ b/src/burn/drv/sega/sys16.h
@@ -102,6 +102,7 @@ extern INT32 System16SoundLatch;
 extern bool System16BTileAlt;
 extern bool Shangon;
 extern bool Hangon;
+extern bool AlienSyndrome;
 extern bool System16Z80Enable;
 
 extern INT32 System16YM2413IRQInterval;
diff --git a/src/burn/drv/sega/sys16_run.cpp b/src/burn/drv/sega/sys16_run.cpp
index fe3189bdd..2efc4a707 100644
--- a/src/burn/drv/sega/sys16_run.cpp
+++ b/src/burn/drv/sega/sys16_run.cpp
@@ -127,6 +127,7 @@ INT32 System16SoundLatch;
 bool System16BTileAlt = false;
 bool Shangon = false;
 bool Hangon = false;
+bool AlienSyndrome = false;
 bool System16Z80Enable = true;
 
 INT32 nSystem16CyclesDone[4];
@@ -2544,6 +2545,8 @@ INT32 System16Exit()
 	System16BTileAlt = false;
 	Shangon = false;
 	Hangon = false;
+	AlienSyndrome = false;
+
 	bSystem16BootlegRender = false;
  	
  	System16YM2413IRQInterval = 0;
@@ -2714,6 +2717,10 @@ INT32 System16BFrame()
 	if (System16Reset) System16DoReset();
 	
 	System16MakeInputs();
+	if (AlienSyndrome) {
+		System16ClearOpposites(&System16Input[1]); // P1
+		System16ClearOpposites(&System16Input[2]); // P2
+	}
 	
 	nCyclesTotal[0] = (INT32)((INT64)System16ClockSpeed * nBurnCPUSpeedAdjust / (0x0100 * 60));
 	nCyclesTotal[1] = 5000000 / 60;