diff --git a/InstructionSets/PowerPC/Instruction.hpp b/InstructionSets/PowerPC/Instruction.hpp
index 349715148..ccfbc6be7 100644
--- a/InstructionSets/PowerPC/Instruction.hpp
+++ b/InstructionSets/PowerPC/Instruction.hpp
@@ -315,7 +315,15 @@ enum class Operation: uint8_t {
 	/// i.e. if rA() is 0 then the value 0 is used, not the contents of r0.
 	stwx,
 
-	subfx, subfcx,
+	subfx,
+
+	/// Subtract from carrying.
+	/// subfc, subfc., subfco, subfco.
+	///
+	/// rD() = -rA() +rB() + 1
+	///
+	/// oe(), rc() apply.
+	subfcx,
 	subfex,
 
 	/// Subtract from immediate carrying
diff --git a/OSBindings/Mac/Clock SignalTests/DingusdevPowerPCTests.mm b/OSBindings/Mac/Clock SignalTests/DingusdevPowerPCTests.mm
index d858c8392..f3e0be5c5 100644
--- a/OSBindings/Mac/Clock SignalTests/DingusdevPowerPCTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/DingusdevPowerPCTests.mm	
@@ -116,6 +116,17 @@ void AssertEqualOperationName(NSString *lhs, NSString *rhs) {
 
 #undef ABCz
 
+#define ABD(x)	\
+			case Operation::x:	\
+				AssertEqualOperationName(operation, @#x);	\
+				[self testABDInstruction:instruction columns:columns testZero:NO];	\
+			break;
+
+//			ABD(subfc);
+//			ABD(subfc_);
+
+#undef ABD
+
 			case Operation::bcx:
 			case Operation::bclrx:
 			case Operation::bcctrx: {