diff --git a/Sources/LanguageServerProtocol/General.swift b/Sources/LanguageServerProtocol/General.swift
index 11d0e05..00a58e5 100644
--- a/Sources/LanguageServerProtocol/General.swift
+++ b/Sources/LanguageServerProtocol/General.swift
@@ -28,7 +28,7 @@ public struct InitializeParams: Codable, Hashable, Sendable {
 	public let workspaceFolders: [WorkspaceFolder]?
 
 	public init(
-		processId: Int,
+		processId: Int?,
 		clientInfo: ClientInfo? = nil,
 		locale: String?,
 		rootPath: String?,
diff --git a/Sources/LanguageServerProtocol/LanguageFeatures/Completion.swift b/Sources/LanguageServerProtocol/LanguageFeatures/Completion.swift
index d07d475..bffdfe3 100644
--- a/Sources/LanguageServerProtocol/LanguageFeatures/Completion.swift
+++ b/Sources/LanguageServerProtocol/LanguageFeatures/Completion.swift
@@ -167,7 +167,7 @@ public struct CompletionItem: Codable, Hashable, Sendable {
 	public let filterText: String?
 	public let insertText: String?
 	public let insertTextFormat: InsertTextFormat?
-	public let textEdit: TextEdit?
+	public let textEdit: TwoTypeOption<TextEdit, InsertReplaceEdit>?
 	public let additionalTextEdits: [TextEdit]?
 	public let commitCharacters: [String]?
 	public let command: Command?
@@ -184,7 +184,7 @@ public struct CompletionItem: Codable, Hashable, Sendable {
 		filterText: String? = nil,
 		insertText: String? = nil,
 		insertTextFormat: InsertTextFormat? = nil,
-		textEdit: TextEdit? = nil,
+		textEdit: TwoTypeOption<TextEdit, InsertReplaceEdit>? = nil,
 		additionalTextEdits: [TextEdit]? = nil,
 		commitCharacters: [String]? = nil,
 		command: Command? = nil,
diff --git a/Sources/LanguageServerProtocol/TextSynchronization.swift b/Sources/LanguageServerProtocol/TextSynchronization.swift
index d4100c6..45c8faa 100644
--- a/Sources/LanguageServerProtocol/TextSynchronization.swift
+++ b/Sources/LanguageServerProtocol/TextSynchronization.swift
@@ -102,6 +102,15 @@ public struct WillSaveTextDocumentParams: Codable, Hashable, Sendable {
 
 public typealias WillSaveWaitUntilResponse = [TextEdit]?
 
+/// A special text edit to provide an insert and a replace operation.
+///
+/// https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#insertReplaceEdit
+public struct InsertReplaceEdit: Codable, Hashable, Sendable {
+    public let newText: String
+    public let insert: LSPRange
+    public let replace: LSPRange
+}
+
 public struct TextEdit: Codable, Hashable, Sendable {
 	public let range: LSPRange
 	public let newText: String