diff --git a/Sources/ArgumentParser/Usage/DumpHelpGenerator.swift b/Sources/ArgumentParser/Usage/DumpHelpGenerator.swift
index 0449c1806..7db5d305e 100644
--- a/Sources/ArgumentParser/Usage/DumpHelpGenerator.swift
+++ b/Sources/ArgumentParser/Usage/DumpHelpGenerator.swift
@@ -9,11 +9,19 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if swift(>=5.11)
+internal import ArgumentParserToolInfo
+internal import class Foundation.JSONEncoder
+#elseif swift(>=5.10)
+import ArgumentParserToolInfo
+import class Foundation.JSONEncoder
+#else
 @_implementationOnly import ArgumentParserToolInfo
 @_implementationOnly import class Foundation.JSONEncoder
+#endif
 
 internal struct DumpHelpGenerator {
-  var toolInfo: ToolInfoV0
+  private var toolInfo: ToolInfoV0
 
   init(_ type: ParsableArguments.Type) {
     self.init(commandStack: [type.asCommand])
diff --git a/Sources/ArgumentParser/Usage/MessageInfo.swift b/Sources/ArgumentParser/Usage/MessageInfo.swift
index cb1da6f4d..bb9a4ea1d 100644
--- a/Sources/ArgumentParser/Usage/MessageInfo.swift
+++ b/Sources/ArgumentParser/Usage/MessageInfo.swift
@@ -9,8 +9,16 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if swift(>=5.11)
+internal import protocol Foundation.LocalizedError
+internal import class Foundation.NSError
+#elseif swift(>=5.10)
+import protocol Foundation.LocalizedError
+import class Foundation.NSError
+#else
 @_implementationOnly import protocol Foundation.LocalizedError
 @_implementationOnly import class Foundation.NSError
+#endif
 
 enum MessageInfo {
   case help(text: String)
diff --git a/Sources/ArgumentParser/Usage/UsageGenerator.swift b/Sources/ArgumentParser/Usage/UsageGenerator.swift
index c6270ae42..e34b94ee6 100644
--- a/Sources/ArgumentParser/Usage/UsageGenerator.swift
+++ b/Sources/ArgumentParser/Usage/UsageGenerator.swift
@@ -9,7 +9,13 @@
 //
 //===----------------------------------------------------------------------===//
 
+#if swift(>=5.11)
+internal import protocol Foundation.LocalizedError
+#elseif swift(>=5.10)
+import protocol Foundation.LocalizedError
+#else
 @_implementationOnly import protocol Foundation.LocalizedError
+#endif
 
 struct UsageGenerator {
   var toolName: String