diff --git a/src/devices/cpu/i386/i486ops.hxx b/src/devices/cpu/i386/i486ops.hxx
index fd346e6109d..d151de8a922 100644
--- a/src/devices/cpu/i386/i486ops.hxx
+++ b/src/devices/cpu/i386/i486ops.hxx
@@ -152,14 +152,16 @@ void i386_device::i486_xadd_rm8_r8()   // Opcode 0x0f c0
 	if( modrm >= 0xc0 ) {
 		uint8_t dst = LOAD_RM8(modrm);
 		uint8_t src = LOAD_REG8(modrm);
+		uint8_t sum = ADD8(dst, src);
 		STORE_REG8(modrm, dst);
-		STORE_RM8(modrm, dst + src);
+		STORE_RM8(modrm, sum);
 		CYCLES(CYCLES_XADD_REG_REG);
 	} else {
 		uint32_t ea = GetEA(modrm,1);
 		uint8_t dst = READ8(ea);
 		uint8_t src = LOAD_REG8(modrm);
-		WRITE8(ea, dst + src);
+		uint8_t sum = ADD8(dst, src);
+		WRITE8(ea, sum);
 		STORE_REG8(modrm, dst);
 		CYCLES(CYCLES_XADD_REG_MEM);
 	}
@@ -171,14 +173,16 @@ void i386_device::i486_xadd_rm16_r16() // Opcode 0x0f c1
 	if( modrm >= 0xc0 ) {
 		uint16_t dst = LOAD_RM16(modrm);
 		uint16_t src = LOAD_REG16(modrm);
+		uint16_t sum = ADD16(dst, src);
 		STORE_REG16(modrm, dst);
-		STORE_RM16(modrm, dst + src);
+		STORE_RM16(modrm, sum);
 		CYCLES(CYCLES_XADD_REG_REG);
 	} else {
 		uint32_t ea = GetEA(modrm,1);
 		uint16_t dst = READ16(ea);
 		uint16_t src = LOAD_REG16(modrm);
-		WRITE16(ea, dst + src);
+		uint16_t sum = ADD16(dst, src);
+		WRITE16(ea, sum);
 		STORE_REG16(modrm, dst);
 		CYCLES(CYCLES_XADD_REG_MEM);
 	}
@@ -190,14 +194,16 @@ void i386_device::i486_xadd_rm32_r32() // Opcode 0x0f c1
 	if( modrm >= 0xc0 ) {
 		uint32_t dst = LOAD_RM32(modrm);
 		uint32_t src = LOAD_REG32(modrm);
+		uint32_t sum = ADD32(dst, src);
 		STORE_REG32(modrm, dst);
-		STORE_RM32(modrm, dst + src);
+		STORE_RM32(modrm, sum);
 		CYCLES(CYCLES_XADD_REG_REG);
 	} else {
 		uint32_t ea = GetEA(modrm,1);
 		uint32_t dst = READ32(ea);
 		uint32_t src = LOAD_REG32(modrm);
-		WRITE32(ea, dst + src);
+		uint32_t sum = ADD32(dst, src);
+		WRITE32(ea, sum);
 		STORE_REG32(modrm, dst);
 		CYCLES(CYCLES_XADD_REG_MEM);
 	}