diff --git a/Sources/Elementary/Core/HtmlBuilder+Tuples.swift b/Sources/Elementary/Core/HtmlBuilder+Tuples.swift
index 775bc6e..9e3cbca 100644
--- a/Sources/Elementary/Core/HtmlBuilder+Tuples.swift
+++ b/Sources/Elementary/Core/HtmlBuilder+Tuples.swift
@@ -44,6 +44,7 @@ public extension HTMLBuilder {
     // variadic generics currently not supported in embedded
     #if !hasFeature(Embedded)
     @inlinable
+    @available(iOS 17, *)
     static func buildBlock<each Content>(_ content: repeat each Content) -> _HTMLTuple<repeat each Content>
     where repeat each Content: HTML {
         _HTMLTuple(repeat each content)
@@ -273,8 +274,10 @@ public struct _HTMLTuple6<V0: HTML, V1: HTML, V2: HTML, V3: HTML, V4: HTML, V5:
 
 // variadic generics currently not supported in embedded
 #if !hasFeature(Embedded)
+@available(iOS 17, *)
 extension _HTMLTuple: Sendable where repeat each Child: Sendable {}
 
+@available(iOS 17, *)
 public struct _HTMLTuple<each Child: HTML>: HTML {
     public let value: (repeat each Child)
 
diff --git a/Sources/Elementary/Rendering/HtmlTextRenderer.swift b/Sources/Elementary/Rendering/HtmlTextRenderer.swift
index 076dc80..bc3e107 100644
--- a/Sources/Elementary/Rendering/HtmlTextRenderer.swift
+++ b/Sources/Elementary/Rendering/HtmlTextRenderer.swift
@@ -1,3 +1,7 @@
+#if os(iOS)
+import Foundation
+#endif
+
 #if !hasFeature(Embedded)
 struct HTMLTextRenderer: _HTMLRendering {
     private var result: [UInt8] = []
@@ -68,7 +72,11 @@ struct PrettyHTMLTextRenderer {
         }
 
         if currentInlineText.contains("\n") {
+            #if os(iOS)
+            currentInlineText = currentInlineText.replacingOccurrences(of: "\n", with: "\n\(currentIndentation)")
+            #else
             currentInlineText.replace("\n", with: "\n\(currentIndentation)")
+            #endif
             addLineBreak()
             result += currentInlineText
             return true
diff --git a/Sources/Elementary/ServerSupport/SendOnceBox.swift b/Sources/Elementary/ServerSupport/SendOnceBox.swift
index eb61348..45f677e 100644
--- a/Sources/Elementary/ServerSupport/SendOnceBox.swift
+++ b/Sources/Elementary/ServerSupport/SendOnceBox.swift
@@ -1,7 +1,7 @@
-#if compiler(>=6.0) && !hasFeature(Embedded) && !os(iOS)
+#if compiler(>=6.0) && !hasFeature(Embedded)
 import Synchronization
 
-@available(macOS 15.0, *)
+@available(iOS 18, macOS 15, *)
 final class SendOnceBox: Sendable, SendOnceBoxing {
     // final class SendOnceBox<Value>: Sendable, SendOnceBoxing {
     typealias Value = any HTML
diff --git a/Sources/Elementary/ServerSupport/SendableAnyHTMLBox.swift b/Sources/Elementary/ServerSupport/SendableAnyHTMLBox.swift
index de9ef7e..44619a7 100644
--- a/Sources/Elementary/ServerSupport/SendableAnyHTMLBox.swift
+++ b/Sources/Elementary/ServerSupport/SendableAnyHTMLBox.swift
@@ -1,8 +1,10 @@
-#if !hasFeature(Embedded) && !os(iOS)
+#if !hasFeature(Embedded)
 /// A wrapper around an `any HTML` value that can be safely sent once.
 ///
 /// Note: For non-sendable values, this will only allow the value to be taken only once.
 /// Sendable values can safely be taken multiple times.
+
+@available(iOS 18, *)
 public struct _SendableAnyHTMLBox: Sendable {
     var storage: Storage