diff --git a/test/testcpu.cpp b/test/testcpu.cpp
index e72d613..21cdf1f 100644
--- a/test/testcpu.cpp
+++ b/test/testcpu.cpp
@@ -12,7 +12,15 @@
 struct CPUTest {
 	CPU cpu { 0 };
 
-	bool isCarry(uint32_t lhs, uint32_t rhs, uint32_t limit_bit) { return cpu.isCarry(lhs, rhs, limit_bit); }
+	bool isCarry(uint32_t limit_bit, uint32_t first, uint32_t second, uint32_t third = 0x0)
+	{
+		return cpu.isCarry(limit_bit, first, second, third);
+	}
+
+	bool isCarrySubtraction(uint32_t limit_bit, uint32_t lhs, uint32_t rhs, uint32_t rhs_extra = 0x0)
+	{
+		return cpu.isCarrySubtraction(limit_bit, lhs, rhs, rhs_extra);
+	}
 };
 
 // -----------------------------------------
@@ -23,27 +31,27 @@ TEST_CASE(CPUIsCarry)
 
 	// 8-bit Half-carry false
 
-	EXPECT_EQ(test.isCarry(56, 17, 0x10), false);
+	EXPECT(test.isCarry(0xf, 56, 17) == false);
 
-	EXPECT_EQ(test.isCarry(16, -1, 0x10), false);
-	EXPECT_EQ(test.isCarry(32, -1, 0x10), false);
-	EXPECT_EQ(test.isCarry(144, -1, 0x10), false);
-	EXPECT_EQ(test.isCarry(211, -20, 0x10), false);
+	EXPECT(test.isCarrySubtraction(0xf, 136, 1) == false);
+	EXPECT(test.isCarrySubtraction(0xf, 219, 20) == false);
+	EXPECT(test.isCarrySubtraction(0xf, 250, 20) == false);
 
 	// 8-bit Half-carry true
 
-	EXPECT_EQ(test.isCarry(46, 34, 0x10), true);
-	EXPECT_EQ(test.isCarry(62, 34, 0x10), true);
+	EXPECT(test.isCarry(0xf, 46, 34) == true);
+	EXPECT(test.isCarry(0xf, 62, 34) == true);
 
-	EXPECT_EQ(test.isCarry(136, -1, 0x10), true);
-	EXPECT_EQ(test.isCarry(219, -20, 0x10), true);
-	EXPECT_EQ(test.isCarry(250, -20, 0x10), true);
+	EXPECT(test.isCarrySubtraction(0xf, 16, 1) == true);
+	EXPECT(test.isCarrySubtraction(0xf, 32, 1) == true);
+	EXPECT(test.isCarrySubtraction(0xf, 144, 1) == true);
+	EXPECT(test.isCarrySubtraction(0xf, 211, 20) == true);
 
 	// 8-bit Full carry false
 
-	EXPECT_EQ(test.isCarry(254, 1, 0x100), false);
+	EXPECT(test.isCarry(0xff, 254, 1) == false);
 
 	// 8-bit Full carry true
 
-	EXPECT_EQ(test.isCarry(254, 2, 0x100), true);
+	EXPECT(test.isCarry(0xff, 254, 2) == true);
 }