diff --git a/highlight-swift/Sources/highlight-swift/highlight_swift.swift b/highlight-swift/Sources/highlight-swift/highlight_swift.swift
index cd12e2c..f15ef8d 100644
--- a/highlight-swift/Sources/highlight-swift/highlight_swift.swift
+++ b/highlight-swift/Sources/highlight-swift/highlight_swift.swift
@@ -2,10 +2,11 @@ import Foundation
 import Splash
 
 @_cdecl("highlight_swift")
-public func highlight(codePtr: UnsafeRawPointer, codeLen: UInt64, htmlLenPtr: UnsafeMutablePointer<UInt64>) -> UnsafeMutableRawPointer {
-    // don't free, the underlying data is owned by rust
-    let code = String(bytesNoCopy: UnsafeMutableRawPointer(mutating: codePtr), length: Int(codeLen), encoding: .utf8, freeWhenDone: false)!
-
+public func highlight(codePtr: UnsafePointer<UInt8>, codeLen: UInt64, htmlLenPtr: UnsafeMutablePointer<UInt64>) -> UnsafeMutableRawPointer {
+    let buf = UnsafeBufferPointer(start: codePtr, count: Int(codeLen))
+    let data = Data(buffer: buf)
+    let code = String(data: data, encoding: .utf8)!
+    
     let highligher = SyntaxHighlighter(format: MyOutputFormat())
     var html = highligher.highlight(code)
     let outPtr = UnsafeMutableBufferPointer<UInt8>.allocate(capacity: html.utf8.count)
diff --git a/highlight-swift/Tests/highlight-swift-tests/HighlightTests.swift b/highlight-swift/Tests/highlight-swift-tests/HighlightTests.swift
index a7eb043..c5518cb 100644
--- a/highlight-swift/Tests/highlight-swift-tests/HighlightTests.swift
+++ b/highlight-swift/Tests/highlight-swift-tests/HighlightTests.swift
@@ -18,7 +18,7 @@ class HighlightTests: XCTestCase {
         var len: UInt64 = 0
         let result = code.withUTF8 { codePtr in
             withUnsafeMutablePointer(to: &len) { lenPtr in
-                highlight(codePtr: UnsafeRawPointer(codePtr.baseAddress!), codeLen: UInt64(codePtr.count), htmlLenPtr: lenPtr)
+                highlight(codePtr: codePtr.baseAddress!, codeLen: UInt64(codePtr.count), htmlLenPtr: lenPtr)
             }
         }
         let start = UnsafePointer(result.assumingMemoryBound(to: UInt8.self))