diff --git a/src/boards/164.c b/src/boards/164.c
index 35052ff..007196b 100644
--- a/src/boards/164.c
+++ b/src/boards/164.c
@@ -348,7 +348,7 @@ static void StateRestore(int version) {
 
 static DECLFR(ReadLow) {
 	switch (A & 0x7700) {
-	case 0x5100: return reg[2] | reg[0] | reg[1] | reg[3] ^ 0xff; break;
+	case 0x5100: return reg[2] | reg[0] | reg[1] | (reg[3] ^ 0xff); break;
 	case 0x5500:
 		if (trigger)
 			return reg[2] | reg[1];   // Lei Dian Huang Bi Ka Qiu Chuan Shuo (NJ046) may broke other games
diff --git a/src/boards/fk23c.c b/src/boards/fk23c.c
index 9ba84a3..7e29877 100644
--- a/src/boards/fk23c.c
+++ b/src/boards/fk23c.c
@@ -99,7 +99,7 @@ static uint64 CartList[] =
 
 int DetectPRGbonus(CartInfo *tmp) {
 	int x, i = 0;
-	uint64 partialmd5;
+	uint64 partialmd5 = 0;
 
 	for (x = 0; x < 8; x++)
 		partialmd5 |= (uint64)tmp->MD5[15 - x] << (x * 8);