diff --git a/Package.swift b/Package.swift
index 01be12e..3091e8e 100755
--- a/Package.swift
+++ b/Package.swift
@@ -49,5 +49,5 @@ let package = Package(
       ]
     )
   ],
-  swiftLanguageVersions: [4]
+  swiftLanguageVersions: [5]
 )
diff --git a/README.md b/README.md
index dcc8b03..07ed639 100755
--- a/README.md
+++ b/README.md
@@ -27,6 +27,11 @@ You can also use the `convert` command to create a binary header map from JSON:
 
 You can discover all the commands and options by using `hmap --help`.
 
+## Requirements
+
+- hmap requires Swift 5.
+- Starting from Xcode 10.2, Swift 5 command line tools require the Swift 5 runtime libraries which are included in macOS Majave 10.4.4. If you're running an earlier version of macOS, you need to install the "Swift 5 Runtime Support for Command Line Tools" available from [More Downloads for Apple Developers](https://developer.apple.com/download/more/).
+
 # Building from Source
 
 ## Xcode
@@ -47,8 +52,8 @@ If you would like to build from the command line, run:
 
 To produce a release build suitable for distribution, run:
 
-    swift build -c release -Xswiftc -static-stdlib
+    swift build -c release
 
 To verify that all tests pass, run:
 
-    swift test
\ No newline at end of file
+    swift test
diff --git a/Sources/HeaderMapCore/BinaryHeaderMap.swift b/Sources/HeaderMapCore/BinaryHeaderMap.swift
index 490ba56..d85b584 100755
--- a/Sources/HeaderMapCore/BinaryHeaderMap.swift
+++ b/Sources/HeaderMapCore/BinaryHeaderMap.swift
@@ -185,10 +185,10 @@ extension BinaryHeaderMap {
     guard preambleSize <= begin, begin < data.count  else { return nil }
     
     let nullByteIndex = data.withUnsafeBytes {
-      (bytes: UnsafePointer<UInt8>) -> Int? in
+      (bytes: UnsafeRawBufferPointer) -> Int? in
       
-      for i in begin..<data.count {
-        if bytes.advanced(by: i).pointee == 0x0 {
+      for i in begin..<bytes.count {
+        if bytes[i] == 0x0 {
           return i
         }
       }
@@ -211,8 +211,10 @@ extension BinaryHeaderMap {
       return nil
     }
     
-    return try data.withUnsafeBytes {
-      return try body($0.advanced(by: offset))
+    return try data.withUnsafeBytes { byteBuffer in
+      let basePointer = byteBuffer.baseAddress?.bindMemory(to: UInt8.self, capacity: byteBuffer.count)
+      let offsetPointer = basePointer?.advanced(by: offset)
+      return try offsetPointer.flatMap { try body($0) }
     }
   }
 }
@@ -252,9 +254,14 @@ func parseHeaderMap(data: Data) throws -> DataHeaderParseResult {
     throw HeaderMapParseError.missingDataHeader
   }
   
-  return try data.withUnsafeBytes { (headerBytes: UnsafePointer<UInt8>) in
+  return try data.withUnsafeBytes { (headerRawBytes: UnsafeRawBufferPointer) in
     typealias H = BinaryHeaderMap.DataHeader
     
+    guard let baseRawPointer = headerRawBytes.baseAddress else {
+      throw HeaderMapParseError.missingDataHeader
+    }
+    
+    let headerBytes = baseRawPointer.bindMemory(to: UInt8.self, capacity: headerRawBytes.count)
     let decoder = ByteBufferDecoder(bytes: headerBytes, byteSwap: false)
     
     let magicValue = decoder.advanceByteSwappable(
diff --git a/Sources/HeaderMapCore/HeaderMapError.swift b/Sources/HeaderMapCore/HeaderMapError.swift
index 8b2652c..a0f4860 100755
--- a/Sources/HeaderMapCore/HeaderMapError.swift
+++ b/Sources/HeaderMapCore/HeaderMapError.swift
@@ -41,6 +41,7 @@ public enum HeaderMapCreateError: LocalizedError {
   case stringWithoutOffsetInTable
   case hashTableFull
   case unhashableKey
+  case emptyDataBuffer
 }
 
 extension HeaderMapError {
@@ -84,6 +85,8 @@ extension HeaderMapCreateError {
       return "Header map is full"
     case .unhashableKey:
       return "Key cannot be hashed"
+    case .emptyDataBuffer:
+      return "Failed to allocate data buffer"
     }
   }
 }
diff --git a/Sources/HeaderMapCore/HeaderMapMaker.swift b/Sources/HeaderMapCore/HeaderMapMaker.swift
index 5377caa..a742fbd 100755
--- a/Sources/HeaderMapCore/HeaderMapMaker.swift
+++ b/Sources/HeaderMapCore/HeaderMapMaker.swift
@@ -136,7 +136,13 @@ fileprivate func makeBucketSection(
   let bucketCount = numberOfBuckets(forEntryCount: entries.count)
   var bytes = Data(count: bucketCount * BinaryHeaderMap.Bucket.packedSize)
   try bytes.withUnsafeMutableBytes {
-    (bytePointer: UnsafeMutablePointer<UInt8>) in
+    (rawBytes: UnsafeMutableRawBufferPointer) in
+    
+    guard let rawBasePointer = rawBytes.baseAddress else {
+      throw HeaderMapCreateError.emptyDataBuffer
+    }
+    
+    let bytePointer = rawBasePointer.bindMemory(to: UInt8.self, capacity: rawBytes.count)
     
     try entries.forEach { (entry) in
       guard let keyHash = entry.key.headerMapHash else {
diff --git a/Sources/HeaderMapCore/extensions/StringExtensions.swift b/Sources/HeaderMapCore/extensions/StringExtensions.swift
index 9c79394..bf8981a 100755
--- a/Sources/HeaderMapCore/extensions/StringExtensions.swift
+++ b/Sources/HeaderMapCore/extensions/StringExtensions.swift
@@ -29,7 +29,7 @@ extension String {
     }
     
     let lowercasedBytes = charBytes.map { $0.asciiLowercased() }
-    return Data(bytes: lowercasedBytes)
+    return Data(lowercasedBytes)
   }
   
   func clangLowercased() throws -> String? {
@@ -42,12 +42,11 @@ extension String {
     else { return nil }
     
     return characterBytes.withUnsafeBytes {
-      (charBlockPointer: UnsafePointer<UInt8>) -> UInt32 in
+      (charBytes: UnsafeRawBufferPointer) -> UInt32 in
       
       var result = UInt32(0)
-      for i in 0 ..< characterBytes.count {
-        let charPointer = charBlockPointer.advanced(by: i)
-        result += UInt32(charPointer.pointee) * 13
+      for i in 0 ..< charBytes.count {
+        result += UInt32(charBytes[i]) * 13
       }
       return result
     }