diff --git a/.jazzy.yaml b/.jazzy.yaml
index 2a57f2b1..2a023beb 100644
--- a/.jazzy.yaml
+++ b/.jazzy.yaml
@@ -3,11 +3,11 @@ sourcekitten_sourcefile: docs.json
 clean: true
 author: Timofey Solomko
 module: SWCompression
-module_version: 4.5.9
+module_version: 4.5.10
 copyright: '© 2021 Timofey Solomko'
 readme: README.md
 github_url: https://github.com/tsolomko/SWCompression
-github_file_prefix: https://github.com/tsolomko/SWCompression/tree/4.5.9
+github_file_prefix: https://github.com/tsolomko/SWCompression/tree/4.5.10
 theme: fullwidth
 
 custom_categories:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 989429ba..d28dce1b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 4.5.10
+
+- Fixed compilation issues on Windows (PR #22 by @trametheka).
+- Performed minor optimizations to BZip2 and Deflate compression functionality.
+- Increased the lowest required version of BitByteData dependency to 1.4.4.
+
 ## 4.5.9
 
 - Improved performance of LZMA/LZMA2 and, consequently, of XZ.
diff --git a/SWCompression.podspec b/SWCompression.podspec
index 4f10dc40..21773455 100644
--- a/SWCompression.podspec
+++ b/SWCompression.podspec
@@ -1,7 +1,7 @@
 Pod::Spec.new do |s|
 
   s.name         = "SWCompression"
-  s.version      = "4.5.9"
+  s.version      = "4.5.10"
   s.summary      = "A framework with functions for working with compression, archives and containers."
   
   s.description  = "A framework with (de)compression algorithms and functions for processing various archives and containers."
@@ -22,7 +22,7 @@ Pod::Spec.new do |s|
 
   s.swift_versions = ["5"]
 
-  s.dependency "BitByteData", "~> 1.4.3"
+  s.dependency "BitByteData", "~> 1.4.4"
 
   s.subspec "Deflate" do |sp|
     sp.source_files = "Sources/{Deflate/*,Common/*,Common/CodingTree/*}.swift"
diff --git a/SWCompression.xcodeproj/SWCompression.plist b/SWCompression.xcodeproj/SWCompression.plist
index ccfd150a..dc55faec 100644
--- a/SWCompression.xcodeproj/SWCompression.plist
+++ b/SWCompression.xcodeproj/SWCompression.plist
@@ -15,9 +15,9 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>4.5.9</string>
+	<string>4.5.10</string>
 	<key>CFBundleVersion</key>
-	<string>76</string>
+	<string>77</string>
 	<key>NSHumanReadableCopyright</key>
 	<string>Copyright © 2021 Timofey Solomko</string>
 </dict>
diff --git a/SWCompression.xcodeproj/TestSWCompression.plist b/SWCompression.xcodeproj/TestSWCompression.plist
index fbfd44a0..1b2400fd 100644
--- a/SWCompression.xcodeproj/TestSWCompression.plist
+++ b/SWCompression.xcodeproj/TestSWCompression.plist
@@ -15,8 +15,8 @@
 	<key>CFBundlePackageType</key>
 	<string>BNDL</string>
 	<key>CFBundleShortVersionString</key>
-	<string>4.5.9</string>
+	<string>4.5.10</string>
 	<key>CFBundleVersion</key>
-	<string>76</string>
+	<string>77</string>
 </dict>
 </plist>
diff --git a/SWCompression.xcodeproj/project.pbxproj b/SWCompression.xcodeproj/project.pbxproj
index 0086e555..9a4dae45 100644
--- a/SWCompression.xcodeproj/project.pbxproj
+++ b/SWCompression.xcodeproj/project.pbxproj
@@ -1258,7 +1258,7 @@
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
-				CURRENT_PROJECT_VERSION = 76;
+				CURRENT_PROJECT_VERSION = 77;
 				DEBUG_INFORMATION_FORMAT = dwarf;
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				ENABLE_TESTABILITY = YES;
@@ -1339,7 +1339,7 @@
 				CLANG_WARN_SUSPICIOUS_MOVE = YES;
 				CLANG_WARN_UNREACHABLE_CODE = YES;
 				CLANG_WARN__DUPLICATE_METHOD_MATCH = YES;
-				CURRENT_PROJECT_VERSION = 76;
+				CURRENT_PROJECT_VERSION = 77;
 				DEBUG_INFORMATION_FORMAT = "dwarf-with-dsym";
 				ENABLE_STRICT_OBJC_MSGSEND = YES;
 				"FRAMEWORK_SEARCH_PATHS[sdk=appletvos*]" = (
@@ -1400,7 +1400,7 @@
 				APPLICATION_EXTENSION_API_ONLY = YES;
 				DEFINES_MODULE = YES;
 				DYLIB_COMPATIBILITY_VERSION = 1;
-				DYLIB_CURRENT_VERSION = 76;
+				DYLIB_CURRENT_VERSION = 77;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				INFOPLIST_FILE = SWCompression.xcodeproj/SWCompression.plist;
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
@@ -1427,7 +1427,7 @@
 				APPLICATION_EXTENSION_API_ONLY = YES;
 				DEFINES_MODULE = YES;
 				DYLIB_COMPATIBILITY_VERSION = 1;
-				DYLIB_CURRENT_VERSION = 76;
+				DYLIB_CURRENT_VERSION = 77;
 				DYLIB_INSTALL_NAME_BASE = "@rpath";
 				INFOPLIST_FILE = SWCompression.xcodeproj/SWCompression.plist;
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
diff --git a/Sources/BZip2/BZip2+Compress.swift b/Sources/BZip2/BZip2+Compress.swift
index 96af5b3d..d46d764e 100644
--- a/Sources/BZip2/BZip2+Compress.swift
+++ b/Sources/BZip2/BZip2+Compress.swift
@@ -79,10 +79,8 @@ extension BZip2: CompressionAlgorithm {
         (out, pointer) = BurrowsWheeler.transform(bytes: out)
 
         let usedBytes = Set(out).sorted()
-        out = mtf(out, characters: usedBytes)
-
         var maxSymbol = 0
-        (out, maxSymbol) = rleOfMtf(out)
+        (out, maxSymbol) = mtfRle(out, characters: usedBytes)
 
         // First, we analyze data and create Huffman trees and selectors.
         // Then we will perform encoding itself.
@@ -258,12 +256,16 @@ extension BZip2: CompressionAlgorithm {
         return out
     }
 
-    private static func rleOfMtf(_ array: [Int]) -> ([Int], Int) {
+    private static func mtfRle(_ array: [Int], characters: [Int]) -> ([Int], Int) {
         var out = [Int]()
+        /// Mutable copy of `characters`.
+        var dictionary = characters
         var lengthOfZerosRun = 0
         var maxSymbol = 1
         for i in 0..<array.count {
-            let byte = array[i]
+            let byte = dictionary.firstIndex(of: array[i])!
+
+            // Run length encoding of zeros.
             if byte == 0 {
                 lengthOfZerosRun += 1
             }
@@ -295,6 +297,10 @@ extension BZip2: CompressionAlgorithm {
                     maxSymbol = newSymbol
                 }
             }
+
+            // Move to the front.
+            let old = dictionary.remove(at: byte)
+            dictionary.insert(old, at: 0)
         }
         // Add the 'end of stream' symbol.
         out.append(maxSymbol + 1)
diff --git a/Sources/Common/CodingTree/EncodingTree.swift b/Sources/Common/CodingTree/EncodingTree.swift
index a0fc7f8f..5fe0a7bb 100644
--- a/Sources/Common/CodingTree/EncodingTree.swift
+++ b/Sources/Common/CodingTree/EncodingTree.swift
@@ -6,22 +6,29 @@
 import Foundation
 import BitByteData
 
+fileprivate struct CodingIndex {
+
+    let treeCode: Int
+    let bitSize: Int
+
+}
+
 final class EncodingTree {
 
     private let bitWriter: BitWriter
 
-    private let codingIndices: [[Int]]
+    private let codingIndices: [CodingIndex]
 
     init(codes: [Code], _ bitWriter: BitWriter, reverseCodes: Bool = false) {
         self.bitWriter = bitWriter
 
-        var codingIndices = Array(repeating: [-1, -1], count: codes.count)
+        var codingIndices = Array(repeating: CodingIndex(treeCode: -1, bitSize: -1), count: codes.count)
 
         for code in codes {
             // Codes have already been reversed.
             // TODO: This assumption may be only correct for Huffman codes.
             let treeCode = reverseCodes ? code.code : code.code.reversed(bits: code.bits)
-            codingIndices[code.symbol] = [treeCode, code.bits]
+            codingIndices[code.symbol] = CodingIndex(treeCode: treeCode, bitSize: code.bits)
         }
         self.codingIndices = codingIndices
 
@@ -33,10 +40,10 @@ final class EncodingTree {
 
         let codingIndex = self.codingIndices[symbol]
 
-        guard codingIndex[0] > -1
+        guard codingIndex.treeCode > -1
             else { fatalError("Symbol is not found.") }
 
-        self.bitWriter.write(number: codingIndex[0], bitsCount: codingIndex[1])
+        self.bitWriter.write(number: codingIndex.treeCode, bitsCount: codingIndex.bitSize)
     }
 
     func bitSize(for stats: [Int]) -> Int {
@@ -45,10 +52,10 @@ final class EncodingTree {
             guard symbol < self.codingIndices.count
                 else { fatalError("Symbol is not found.") }
             let codingIndex = self.codingIndices[symbol]
-            guard codingIndex[0] > -1
+            guard codingIndex.treeCode > -1
                 else { fatalError("Symbol is not found.") }
 
-            totalSize += count * codingIndex[1]
+            totalSize += count * codingIndex.bitSize
         }
         return totalSize
     }
diff --git a/Sources/swcomp/main.swift b/Sources/swcomp/main.swift
index 5ca7c1c9..16d1931f 100644
--- a/Sources/swcomp/main.swift
+++ b/Sources/swcomp/main.swift
@@ -7,7 +7,7 @@ import Foundation
 import SWCompression
 import SwiftCLI
 
-let cli = CLI(name: "swcomp", version: "4.5.9",
+let cli = CLI(name: "swcomp", version: "4.5.10",
               description: """
                            swcomp - a small command-line client for SWCompression framework.
                            Serves as an example of SWCompression usage.