diff --git a/src/mess/machine/nes_jy.c b/src/mess/machine/nes_jy.c
index 3568c650559..7f415063498 100644
--- a/src/mess/machine/nes_jy.c
+++ b/src/mess/machine/nes_jy.c
@@ -271,11 +271,11 @@ READ8_MEMBER(nes_jy_typea_device::read_l)
 	}
 	if (offset >= 0x1800)
 	{
-		if ((offset & 3) & 3 == 0)
+		if ((offset & 3) == 0)
 			return (m_mul[0] * m_mul[1]) & 0xff;
-		if ((offset & 3) & 3 == 1)
+		if ((offset & 3) == 1)
 			return ((m_mul[0] * m_mul[1]) >> 8) & 0xff;
-		if ((offset & 3) & 3 == 3)
+		if ((offset & 3) == 3)
 			return m_latch;
 	}
 	return ((offset + 0x4000) & 0xff00) >> 8;   // open bus
@@ -290,9 +290,9 @@ WRITE8_MEMBER(nes_jy_typea_device::write_l)
 	{
 		if ((offset & 3) == 0)
 			m_mul[0] = data;
-		if ((offset & 3) & 3 == 1)
+		if ((offset & 3) == 1)
 			m_mul[1] = data;
-		if ((offset & 3) & 3 == 3)
+		if ((offset & 3) == 3)
 			m_latch = data;
 	}
 }
diff --git a/src/mess/machine/nes_mmc3_clones.c b/src/mess/machine/nes_mmc3_clones.c
index 705f559035c..8456978ec9b 100644
--- a/src/mess/machine/nes_mmc3_clones.c
+++ b/src/mess/machine/nes_mmc3_clones.c
@@ -2496,7 +2496,7 @@ WRITE8_MEMBER(nes_bmc_411120c_device::write_m)
 
 void nes_bmc_830118c_device::prg_cb(int start, int bank)
 {
-	if (m_reg & 0x0c != 0x0c)
+	if ((m_reg & 0x0c) != 0x0c)
 		prg8_x(start, (bank & 0x0f) | ((m_reg & 0x0c) << 2));
 	else
 	{
diff --git a/src/mess/machine/nes_pirate.c b/src/mess/machine/nes_pirate.c
index 64e7710d3ec..359a0df56e3 100644
--- a/src/mess/machine/nes_pirate.c
+++ b/src/mess/machine/nes_pirate.c
@@ -1064,7 +1064,7 @@ WRITE8_MEMBER(nes_whero_device::write_h)
 
 		case 0x1002:
 		case 0x1080:
-			if (m_reg != data & 2)
+			if (m_reg != (data & 2))
 			{
 				m_reg = data & 2;
 				// swap banks!
@@ -1126,7 +1126,7 @@ WRITE8_MEMBER(nes_43272_device::write_h)
 {
 	LOG_MMC(("unl_43272 write_h, offset: %04x, data: %02x\n", offset, data));
 
-	if (m_latch & 0x81 == 0x81)
+	if ((m_latch & 0x81) == 0x81)
 		prg32((m_latch & 0x38) >> 3);
 
 	m_latch = offset & 0xffff;