diff --git a/Source/CarthageKit/BuildSettings.swift b/Source/CarthageKit/BuildSettings.swift
index 8bd327f236..22efb417e2 100644
--- a/Source/CarthageKit/BuildSettings.swift
+++ b/Source/CarthageKit/BuildSettings.swift
@@ -89,11 +89,11 @@ public struct BuildSettings {
 							return
 						}
 
-						if let result = self.targetSettingsRegex.firstMatch(in: line, range: NSRange(location: 0, length: line.utf16.count)) {
-							let targetRange = result.range(at: 1)
+						if let result = self.targetSettingsRegex.firstMatch(in: line, range: NSRange(line.startIndex..., in: line)) {
+							let targetRange = Range(result.range(at: 1), in: line)!
 
 							flushTarget()
-							currentTarget = (line as NSString).substring(with: targetRange)
+							currentTarget = line.substring(with: targetRange)
 							return
 						}
 
diff --git a/Source/CarthageKit/GitHub.swift b/Source/CarthageKit/GitHub.swift
index 90e75c7d8a..320a1c6446 100644
--- a/Source/CarthageKit/GitHub.swift
+++ b/Source/CarthageKit/GitHub.swift
@@ -39,10 +39,10 @@ extension Repository {
 	/// Enterprise instances.
 	public static func fromIdentifier(_ identifier: String) -> Result<(Server, Repository), ScannableError> {
 		// ‘owner/name’ → GitHub.com
-		let range = NSRange(location: 0, length: identifier.utf16.count)
+		let range = NSRange(identifier.startIndex..., in: identifier)
 		if let match = nwoRegex.firstMatch(in: identifier, range: range) {
-			let owner = (identifier as NSString).substring(with: match.range(at: 1))
-			let name = (identifier as NSString).substring(with: match.range(at: 2))
+			let owner = identifier.substring(with: Range(match.range(at: 1), in: identifier)!)
+			let name = identifier.substring(with: Range(match.range(at: 2), in: identifier)!)
 			return .success((.dotCom, self.init(owner: owner, name: strippingGitSuffix(name))))
 		}
 
diff --git a/Source/CarthageKit/Xcode.swift b/Source/CarthageKit/Xcode.swift
index 5fd2144168..7e15ba5562 100644
--- a/Source/CarthageKit/Xcode.swift
+++ b/Source/CarthageKit/Xcode.swift
@@ -37,7 +37,7 @@ private func parseSwiftVersionCommand(output: String?) -> String? {
 	guard
 		let output = output,
 		let regex = try? NSRegularExpression(pattern: "Apple Swift version ([0-9.]+) .*\\((.+)\\)", options: []),
-		let match = regex.firstMatch(in: output, options: [], range: NSRange(location: 0, length: output.characters.count))
+		let match = regex.firstMatch(in: output, options: [], range: NSRange(output.startIndex..., in: output))
 		else
 	{
 		return nil
@@ -45,8 +45,9 @@ private func parseSwiftVersionCommand(output: String?) -> String? {
 
 	guard match.numberOfRanges == 3 else { return nil }
 
-	let nsString = output as NSString
-	return "\(nsString.substring(with: match.range(at: 1))) (\(nsString.substring(with: match.range(at: 2))))"
+	let first = output.substring(with: Range(match.range(at: 1), in: output)!)
+	let second = output.substring(with: Range(match.range(at: 2), in: output)!)
+	return "\(first) (\(second))"
 }
 
 /// Determines the Swift version of a framework at a given `URL`.
@@ -581,10 +582,10 @@ private func build(sdk: SDK, with buildArgs: BuildArguments, in workingDirectory
 						pattern: "-- \(platformName) [0-9.]+ --\\n.*?\\(([0-9A-Z]{8}-([0-9A-Z]{4}-){3}[0-9A-Z]{12})\\)",
 						options: []
 					)
-					let lastDeviceResult = regex.matches(in: string, range: NSRange(location: 0, length: string.utf16.count)).last
+					let lastDeviceResult = regex.matches(in: string, range: NSRange(string.startIndex..., in: string)).last
 					return lastDeviceResult.map { result in
 						// We use the ID here instead of the name as it's guaranteed to be unique, the name isn't.
-						let deviceID = (string as NSString).substring(with: result.range(at: 1))
+						let deviceID = string.substring(with: Range(result.range(at: 1), in: string)!)
 						return "platform=\(platformName) Simulator,id=\(deviceID)"
 					}
 				}
diff --git a/Source/XCDBLD/XcodeVersion.swift b/Source/XCDBLD/XcodeVersion.swift
index 6c30541d57..8b23714840 100644
--- a/Source/XCDBLD/XcodeVersion.swift
+++ b/Source/XCDBLD/XcodeVersion.swift
@@ -22,14 +22,13 @@ public struct XcodeVersion {
 	}
 
 	internal init?(xcodebuildOutput: String) {
-		let range = NSRange(location: 0, length: xcodebuildOutput.utf16.count)
+		let range = NSRange(xcodebuildOutput.startIndex..., in: xcodebuildOutput)
 		guard let match = XcodeVersion.regex.firstMatch(in: xcodebuildOutput, range: range) else {
 			return nil
 		}
 
-		let nsString = xcodebuildOutput as NSString
-		let version = nsString.substring(with: match.range(at: 1))
-		let buildVersion = nsString.substring(with: match.range(at: 2))
+		let version = xcodebuildOutput.substring(with: Range(match.range(at: 1), in: xcodebuildOutput)!)
+		let buildVersion = xcodebuildOutput.substring(with: Range(match.range(at: 2), in: xcodebuildOutput)!)
 
 		self.init(version: version, buildVersion: buildVersion)
 	}