diff --git a/Sources/SWBUtil/POSIX.swift b/Sources/SWBUtil/POSIX.swift
index 1d3576c6..6a4e85d4 100644
--- a/Sources/SWBUtil/POSIX.swift
+++ b/Sources/SWBUtil/POSIX.swift
@@ -14,12 +14,10 @@ import SWBLibc
 
 public import protocol Foundation.LocalizedError
 
-#if os(Windows)
 #if canImport(System)
-import System
+public import System
 #else
-import SystemPackage
-#endif
+public import SystemPackage
 #endif
 
 public enum POSIX: Sendable {
@@ -78,12 +76,16 @@ public enum POSIX: Sendable {
 }
 
 public struct POSIXError: Error, LocalizedError, CustomStringConvertible, Equatable {
-    public let code: Int32
+    public let underlyingError: Errno
     public let context: String?
     public let arguments: [String]
 
+    public var code: Int32 {
+        underlyingError.rawValue
+    }
+
     public init(_ code: Int32, context: String? = nil, _ arguments: [String]) {
-        self.code = code
+        self.underlyingError = Errno(rawValue: code)
         self.context = context
         self.arguments = arguments
     }
@@ -93,7 +95,7 @@ public struct POSIXError: Error, LocalizedError, CustomStringConvertible, Equata
     }
 
     public var description: String {
-        let end = "\(String(cString: strerror(code))) (\(code))"
+        let end = "\(underlyingError.description) (\(code))"
         if let context {
             return "\(context)(\(arguments.joined(separator: ", "))): \(end)"
         }
diff --git a/Sources/SWBUtil/PbxCp.swift b/Sources/SWBUtil/PbxCp.swift
index f5be8a02..19c14c11 100644
--- a/Sources/SWBUtil/PbxCp.swift
+++ b/Sources/SWBUtil/PbxCp.swift
@@ -432,7 +432,8 @@ fileprivate func copyTree(_ srcPath: Path, _ dstPath: Path, options: CopyOptions
         do {
             _srcPath = try localFS.realpath(srcPath)
         } catch let error as POSIXError {
-            outStream <<< "error: \(srcPath.str): \(String(cString: strerror(error.code)))\n"
+            // TODO: Does this really need to print specially for POSIXError?
+            outStream <<< "error: \(srcPath.str): \(error.underlyingError.description)\n"
             return false
         } catch {
             outStream <<< "error: \(srcPath.str): \(error.localizedDescription)\n"
@@ -441,7 +442,8 @@ fileprivate func copyTree(_ srcPath: Path, _ dstPath: Path, options: CopyOptions
         do {
             _dstPath = try localFS.realpath(dstPath)
         } catch let error as POSIXError {
-            outStream <<< "error: \(dstPath.str): \(String(cString: strerror(error.code)))\n"
+            // TODO: Does this really need to print specially for POSIXError?
+            outStream <<< "error: \(dstPath.str): \(error.underlyingError.description)\n"
             return false
         } catch {
             outStream <<< "error: \(srcPath.str): \(error.localizedDescription)\n"