diff --git a/Logger.xcodeproj/project.pbxproj b/Logger.xcodeproj/project.pbxproj
index 8376b6e..317817a 100644
--- a/Logger.xcodeproj/project.pbxproj
+++ b/Logger.xcodeproj/project.pbxproj
@@ -23,6 +23,7 @@
 		2ED103E12135C61100EB3683 /* LogrotateTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2ED103E02135C61100EB3683 /* LogrotateTests.swift */; };
 		2ED103E32135D3FB00EB3683 /* SizeLimitedFileTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2ED103E22135D3FB00EB3683 /* SizeLimitedFileTests.swift */; };
 		2ED103E52138553B00EB3683 /* DiskLoggerTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2ED103E42138553B00EB3683 /* DiskLoggerTests.swift */; };
+		2ED83781236A19A60008C01F /* OSFileHandle.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2ED83780236A19A60008C01F /* OSFileHandle.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -66,6 +67,7 @@
 		2ED103E02135C61100EB3683 /* LogrotateTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LogrotateTests.swift; sourceTree = "<group>"; };
 		2ED103E22135D3FB00EB3683 /* SizeLimitedFileTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SizeLimitedFileTests.swift; sourceTree = "<group>"; };
 		2ED103E42138553B00EB3683 /* DiskLoggerTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DiskLoggerTests.swift; sourceTree = "<group>"; };
+		2ED83780236A19A60008C01F /* OSFileHandle.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OSFileHandle.swift; sourceTree = "<group>"; };
 		2EDA8AE8213ACCFF00FE5840 /* README.md */ = {isa = PBXFileReference; lastKnownFileType = net.daringfireball.markdown; path = README.md; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
@@ -149,6 +151,7 @@
 				2EBF4B552122B598008E4117 /* SizeLimitedFile.swift */,
 				2EBF4B562122B598008E4117 /* Logrotate.swift */,
 				2ED077DA2132B0320058EEFC /* OSFileManager.swift */,
+				2ED83780236A19A60008C01F /* OSFileHandle.swift */,
 			);
 			path = DiskLogger;
 			sourceTree = "<group>";
@@ -259,6 +262,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				2EBF4B582122B598008E4117 /* SizeLimitedFile.swift in Sources */,
+				2ED83781236A19A60008C01F /* OSFileHandle.swift in Sources */,
 				2EBF4B572122B598008E4117 /* DiskLogger.swift in Sources */,
 				2EBF4B4C2122AF53008E4117 /* NullLogger.swift in Sources */,
 				2EBF4B3E2122AA34008E4117 /* Logger.swift in Sources */,
diff --git a/Logger/Loggers/DiskLogger/DiskLogger.swift b/Logger/Loggers/DiskLogger/DiskLogger.swift
index 3ffc4e2..395ba57 100644
--- a/Logger/Loggers/DiskLogger/DiskLogger.swift
+++ b/Logger/Loggers/DiskLogger/DiskLogger.swift
@@ -148,14 +148,7 @@ private class FileWriterFactory: SizeLimitedFileFactory {
 }
 
 private class FileHandleFactory: FileFactory {
-    func makeInstance(forWritingTo: URL) throws -> File {
+    func makeInstance(forWritingTo: URL) throws -> OSFileHandle {
         return try FileHandle(forWritingTo: forWritingTo)
     }
 }
-
-extension FileHandle: File {
-    
-    func swift_write(_ data: Data) throws {
-        try __write(data, error: ())
-    }
-}
diff --git a/Logger/Loggers/DiskLogger/OSFileHandle.swift b/Logger/Loggers/DiskLogger/OSFileHandle.swift
new file mode 100644
index 0000000..dfe5bb9
--- /dev/null
+++ b/Logger/Loggers/DiskLogger/OSFileHandle.swift
@@ -0,0 +1,23 @@
+//
+//  OSFileHandle.swift
+//  Logger
+//
+//  Created by Wojciech Nagrodzki on 30/10/2019.
+//  Copyright © 2019 Wojciech Nagrodzki. All rights reserved.
+//
+
+import Foundation
+
+protocol OSFileHandle {
+    func seekToEndOfFile() -> UInt64
+    func swift_write(_ data: Data) throws
+    func synchronizeFile()
+    func closeFile()
+}
+
+extension FileHandle: OSFileHandle {
+    
+    func swift_write(_ data: Data) throws {
+        try __write(data, error: ())
+    }
+}
diff --git a/Logger/Loggers/DiskLogger/SizeLimitedFile.swift b/Logger/Loggers/DiskLogger/SizeLimitedFile.swift
index 29fc221..c93b5c0 100644
--- a/Logger/Loggers/DiskLogger/SizeLimitedFile.swift
+++ b/Logger/Loggers/DiskLogger/SizeLimitedFile.swift
@@ -24,15 +24,8 @@
 
 import Foundation
 
-protocol File {
-    func seekToEndOfFile() -> UInt64
-    func swift_write(_ data: Data) throws
-    func synchronizeFile()
-    func closeFile()
-}
-
 protocol FileFactory {
-    func makeInstance(forWritingTo: URL) throws -> File
+    func makeInstance(forWritingTo: URL) throws -> OSFileHandle
 }
 
 /// Write failed as allowed size limit would be exceeded.
@@ -55,7 +48,7 @@ protocol SizeLimitedFile {
 /// Allows writing to a file while respecting allowed size limit.
 final class SizeLimitedFileImpl {
     
-    private let file: File
+    private let file: OSFileHandle
     private let sizeLimit: UInt64
     private var currentSize: UInt64
     
diff --git a/UnitTests/SizeLimitedFileTests.swift b/UnitTests/SizeLimitedFileTests.swift
index c6e7987..e65dde0 100644
--- a/UnitTests/SizeLimitedFileTests.swift
+++ b/UnitTests/SizeLimitedFileTests.swift
@@ -69,7 +69,7 @@ private class UnopenableFileFactory: FileFactory {
     
     struct OpenFileError: Error {}
     
-    func makeInstance(forWritingTo: URL) throws -> File {
+    func makeInstance(forWritingTo: URL) throws -> OSFileHandle {
         throw OpenFileError()
     }
 }
@@ -78,12 +78,12 @@ private class FileMockFactory: FileFactory {
     
     let mock = FileMock()
     
-    func makeInstance(forWritingTo: URL) throws -> File {
+    func makeInstance(forWritingTo: URL) throws -> OSFileHandle {
         return mock
     }
 }
 
-private class FileMock: File {
+private class FileMock: OSFileHandle {
     
     private(set) var writtenData = Data()
     private(set) var synchronizeFileCallCount = 0