diff --git a/OSBindings/Mac/Clock SignalTests/Z80MachineCycleTests.swift b/OSBindings/Mac/Clock SignalTests/Z80MachineCycleTests.swift
index 4295e6cf3..e719e977c 100644
--- a/OSBindings/Mac/Clock SignalTests/Z80MachineCycleTests.swift	
+++ b/OSBindings/Mac/Clock SignalTests/Z80MachineCycleTests.swift	
@@ -24,6 +24,7 @@ class Z80MachineCycleTests: XCTestCase {
 					case .portRead:				opName = "i"
 					case .portWrite:			opName = "o"
 					case .internalOperation:	opName = "iop"
+					default:					opName = "?"
 				}
 				return "\(opName) \(length)"
 			}
@@ -35,7 +36,7 @@ class Z80MachineCycleTests: XCTestCase {
 		// Create a machine and install the supplied program at address 0, setting the PC to run from there
 		let machine = CSTestMachineZ80()
 		machine.setValue(0x0000, for: .programCounter)
-		machine.setData(Data(bytes: program), atAddress: 0x0000)
+		machine.setData(Data(_: program), atAddress: 0x0000)
 
 		// Figure out the total number of cycles implied by the bus cycles
 		var totalCycles: Int32 = 0
diff --git a/OSBindings/Mac/Clock SignalTests/Z80MemptrTests.swift b/OSBindings/Mac/Clock SignalTests/Z80MemptrTests.swift
index 6fc3c5ce5..7ef2513f4 100644
--- a/OSBindings/Mac/Clock SignalTests/Z80MemptrTests.swift	
+++ b/OSBindings/Mac/Clock SignalTests/Z80MemptrTests.swift	
@@ -14,7 +14,7 @@ class Z80MemptrTests: XCTestCase {
 	private func test(program : [UInt8], length : Int32, initialValue : UInt16) -> UInt16 {
 		// Create a machine and install the supplied program at address 0, setting the PC to run from there
 		machine.setValue(0x0000, for: .programCounter)
-		machine.setData(Data(bytes: program), atAddress: 0x0000)
+		machine.setData(Data(_: program), atAddress: 0x0000)
 
 		// Set the initial value of memptr, run for the requested number of cycles,
 		// return the new value
@@ -316,7 +316,7 @@ class Z80MemptrTests: XCTestCase {
 		let program: [UInt8] = [
 			0xed, 0xa1
 		]
-		machine.setData(Data(bytes: program), atAddress: 0x0000)
+		machine.setData(Data(_: program), atAddress: 0x0000)
 		machine.setValue(0, for: .memPtr)
 
 		for c in 1 ..< 65536 {
@@ -332,7 +332,7 @@ class Z80MemptrTests: XCTestCase {
 		let program: [UInt8] = [
 			0xed, 0xa9
 		]
-		machine.setData(Data(bytes: program), atAddress: 0x0000)
+		machine.setData(Data(_: program), atAddress: 0x0000)
 		machine.setValue(0, for: .memPtr)
 
 		for c in 1 ..< 65536 {