diff --git a/Sources/SwiftCoroutine/Coroutine/Coroutine/Coroutine.swift b/Sources/SwiftCoroutine/Coroutine/Coroutine/Coroutine.swift
index b35143e..23a2d82 100644
--- a/Sources/SwiftCoroutine/Coroutine/Coroutine/Coroutine.swift
+++ b/Sources/SwiftCoroutine/Coroutine/Coroutine/Coroutine.swift
@@ -15,16 +15,6 @@ import Dispatch
 ///
 public struct Coroutine {
     
-    @inlinable static func current() throws -> CoroutineProtocol {
-        if let coroutine = ThreadCoroutineWrapper.current.coroutine { return coroutine }
-        throw CoroutineError.mustBeCalledInsideCoroutine
-    }
-    
-    /// Returns `true` if this property is called inside a coroutine.
-    @inlinable public static var isInsideCoroutine: Bool {
-        ThreadCoroutineWrapper.current.coroutine != nil
-    }
-    
     // MARK: - await
     
     /// Suspends a coroutine поки не буде викликаний callback.
diff --git a/Sources/SwiftCoroutine/Coroutine/CoroutineProtocol/CoroutineProtocol.swift b/Sources/SwiftCoroutine/Coroutine/CoroutineProtocol/CoroutineProtocol.swift
index e33d235..b3d1adc 100644
--- a/Sources/SwiftCoroutine/Coroutine/CoroutineProtocol/CoroutineProtocol.swift
+++ b/Sources/SwiftCoroutine/Coroutine/CoroutineProtocol/CoroutineProtocol.swift
@@ -6,6 +6,12 @@
 //  Copyright © 2020 Alex Belozierov. All rights reserved.
 //
 
+#if os(Linux)
+import Glibc
+#else
+import Darwin
+#endif
+
 @usableFromInline protocol CoroutineProtocol: class {
     
     typealias StackSize = Coroutine.StackSize
@@ -17,12 +23,46 @@
 
 extension CoroutineProtocol {
     
-    @inlinable func performAsCurrent<T>(_ block: () -> T) -> T {
-        let wrapper = ThreadCoroutineWrapper.current
-        let caller = wrapper.coroutine
-        wrapper.coroutine = self
-        defer { wrapper.coroutine = caller }
-        return block()
+    @inlinable internal func performAsCurrent<T>(_ block: () -> T) -> T {
+        let unmanaged = Unmanaged.passRetained(self)
+        defer { unmanaged.release() }
+        if let caller = pthread_getspecific(.coroutine) {
+            pthread_setspecific(.coroutine, unmanaged.toOpaque())
+            defer { pthread_setspecific(.coroutine, caller) }
+            return block()
+        } else {
+            pthread_setspecific(.coroutine, unmanaged.toOpaque())
+            defer { pthread_setspecific(.coroutine, nil) }
+            return block()
+        }
+    }
+    
+}
+
+extension Coroutine {
+    
+    /// Returns `true` if this property is called inside a coroutine.
+    @inlinable public static var isInsideCoroutine: Bool {
+        pthread_getspecific(.coroutine) != nil
+    }
+    
+    @inlinable static func current() throws -> CoroutineProtocol {
+        guard let pointer = pthread_getspecific(.coroutine)
+            else { throw CoroutineError.mustBeCalledInsideCoroutine }
+        return Unmanaged<AnyObject>.fromOpaque(pointer).takeUnretainedValue() as! CoroutineProtocol
     }
     
 }
+
+extension pthread_key_t {
+    
+    @usableFromInline internal static let coroutine: pthread_key_t = {
+        let key = UnsafeMutablePointer<pthread_key_t>.allocate(capacity: 1)
+        pthread_key_create(key, nil)
+        defer { key.deallocate() }
+        return key.pointee
+    }()
+    
+}
+
+
diff --git a/Sources/SwiftCoroutine/Coroutine/CoroutineProtocol/ThreadCoroutineWrapper.swift b/Sources/SwiftCoroutine/Coroutine/CoroutineProtocol/ThreadCoroutineWrapper.swift
deleted file mode 100644
index b3ce570..0000000
--- a/Sources/SwiftCoroutine/Coroutine/CoroutineProtocol/ThreadCoroutineWrapper.swift
+++ /dev/null
@@ -1,35 +0,0 @@
-//
-//  ThreadCoroutineWrapper.swift
-//  SwiftCoroutine
-//
-//  Created by Alex Belozierov on 07.03.2020.
-//  Copyright © 2020 Alex Belozierov. All rights reserved.
-//
-
-#if os(Linux)
-import Glibc
-#else
-import Darwin
-#endif
-
-@usableFromInline final class ThreadCoroutineWrapper {
-    
-    @usableFromInline var coroutine: CoroutineProtocol?
-    
-    @usableFromInline static var current: ThreadCoroutineWrapper {
-        if let pointer = pthread_getspecific(key) {
-            return Unmanaged<ThreadCoroutineWrapper>.fromOpaque(pointer).takeUnretainedValue()
-        }
-        let wrapper = Unmanaged.passRetained(ThreadCoroutineWrapper())
-        pthread_setspecific(key, wrapper.toOpaque())
-        return wrapper.takeUnretainedValue()
-    }
-
-    private static let key: pthread_key_t = {
-        let key = UnsafeMutablePointer<pthread_key_t>.allocate(capacity: 1)
-        pthread_key_create(key, nil)
-        defer { key.deallocate() }
-        return key.pointee
-    }()
-    
-}
diff --git a/SwiftCoroutine.xcodeproj/project.pbxproj b/SwiftCoroutine.xcodeproj/project.pbxproj
index f8b4ac8..4e7d970 100644
--- a/SwiftCoroutine.xcodeproj/project.pbxproj
+++ b/SwiftCoroutine.xcodeproj/project.pbxproj
@@ -27,8 +27,6 @@
 		1A363CBD2413D004000CF996 /* StackfullCoroutine.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1A363CBB2413D004000CF996 /* StackfullCoroutine.swift */; };
 		1A363CBF2413D03B000CF996 /* CoroutineProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1A363CBE2413D03B000CF996 /* CoroutineProtocol.swift */; };
 		1A363CC02413D03B000CF996 /* CoroutineProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1A363CBE2413D03B000CF996 /* CoroutineProtocol.swift */; };
-		1A363CC22413D077000CF996 /* ThreadCoroutineWrapper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1A363CC12413D077000CF996 /* ThreadCoroutineWrapper.swift */; };
-		1A363CC32413D077000CF996 /* ThreadCoroutineWrapper.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1A363CC12413D077000CF996 /* ThreadCoroutineWrapper.swift */; };
 		1A43084523C094EC001A89EA /* DispatchSourceTimer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1A43084423C094EC001A89EA /* DispatchSourceTimer.swift */; };
 		1A43084623C094EC001A89EA /* DispatchSourceTimer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1A43084423C094EC001A89EA /* DispatchSourceTimer.swift */; };
 		1A47C25023D73D3F004CC7B1 /* CoroutineTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1A47C24F23D73D3F004CC7B1 /* CoroutineTests.swift */; };
@@ -135,7 +133,6 @@
 		1A3583FE23DD796A0086A6E6 /* CoFuture1+whenComplete.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "CoFuture1+whenComplete.swift"; sourceTree = "<group>"; };
 		1A363CBB2413D004000CF996 /* StackfullCoroutine.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StackfullCoroutine.swift; sourceTree = "<group>"; };
 		1A363CBE2413D03B000CF996 /* CoroutineProtocol.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoroutineProtocol.swift; sourceTree = "<group>"; };
-		1A363CC12413D077000CF996 /* ThreadCoroutineWrapper.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ThreadCoroutineWrapper.swift; sourceTree = "<group>"; };
 		1A43084423C094EC001A89EA /* DispatchSourceTimer.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DispatchSourceTimer.swift; sourceTree = "<group>"; };
 		1A47C24F23D73D3F004CC7B1 /* CoroutineTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CoroutineTests.swift; sourceTree = "<group>"; };
 		1A4C6DAC2416AB2C00EF2974 /* FifoQueue.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FifoQueue.swift; sourceTree = "<group>"; };
@@ -294,7 +291,6 @@
 		1A599E51241ACD7B007E744F /* CoroutineProtocol */ = {
 			isa = PBXGroup;
 			children = (
-				1A363CC12413D077000CF996 /* ThreadCoroutineWrapper.swift */,
 				1A363CBE2413D03B000CF996 /* CoroutineProtocol.swift */,
 			);
 			path = CoroutineProtocol;
@@ -694,7 +690,6 @@
 				1AFFF6ED23C8BDEA0079FF73 /* CoFutureError.swift in Sources */,
 				1A8129A52417D49900AE061C /* CoroutineDispatcher.swift in Sources */,
 				F8CD25E92019A01600952299 /* CCoroutine.c in Sources */,
-				1A363CC22413D077000CF996 /* ThreadCoroutineWrapper.swift in Sources */,
 				1A43084523C094EC001A89EA /* DispatchSourceTimer.swift in Sources */,
 				1A790E8423E5D7A9007056EC /* Coroutine.swift in Sources */,
 				1A65BABB239CE05D004C1716 /* CoroutineContext.swift in Sources */,
@@ -755,7 +750,6 @@
 				1A65BAC2239CEFED004C1716 /* CoroutineContext.swift in Sources */,
 				1A8129A62417D49900AE061C /* CoroutineDispatcher.swift in Sources */,
 				F8CD25ED2019A0F800952299 /* CCoroutine.c in Sources */,
-				1A363CC32413D077000CF996 /* ThreadCoroutineWrapper.swift in Sources */,
 				1A790E8523E5D7A9007056EC /* Coroutine.swift in Sources */,
 				1A43084623C094EC001A89EA /* DispatchSourceTimer.swift in Sources */,
 				1A9C14DF23BB824400E13203 /* CoFuture2+await.swift in Sources */,