diff --git a/Platform/WinRT/Readium/Readium/ThreadEmulation.h b/Platform/WinRT/Readium/Readium/ThreadEmulation.h
index 37deabca9..ded321357 100644
--- a/Platform/WinRT/Readium/Readium/ThreadEmulation.h
+++ b/Platform/WinRT/Readium/Readium/ThreadEmulation.h
@@ -34,6 +34,10 @@
 
 namespace ThreadEmulation
 {
+	#ifndef TLS_OUT_OF_INDEXES
+	# define TLS_OUT_OF_INDEXES ((DWORD)0xffffffff)
+	#endif
+
     #ifndef CREATE_SUSPENDED
     #define CREATE_SUSPENDED 0x00000004
     #endif
diff --git a/Platform/WinRT/Readium/Readium/WinInitialization.cpp b/Platform/WinRT/Readium/Readium/WinInitialization.cpp
index 0fea1aa44..c60872d4d 100644
--- a/Platform/WinRT/Readium/Readium/WinInitialization.cpp
+++ b/Platform/WinRT/Readium/Readium/WinInitialization.cpp
@@ -1,9 +1,13 @@
 #include "WinInitialization.h"
+#include "run_loop.h"
 
 BEGIN_READIUM_API
 
 void Initialization::InitializeSdk()
 {
+#if EPUB_PLATFORM(WINRT)
+	ePub3::RunLoop::InitRunLoopTLSKey();
+#endif
 	ePub3::InitializeSdk();
 }
 
diff --git a/Platform/WinRT/Readium/Readium/WinInitialization.h b/Platform/WinRT/Readium/Readium/WinInitialization.h
index 9981232f2..56ea90c4c 100644
--- a/Platform/WinRT/Readium/Readium/WinInitialization.h
+++ b/Platform/WinRT/Readium/Readium/WinInitialization.h
@@ -10,14 +10,8 @@ public ref class Initialization sealed
 {
 
 public:
-
-	static void InitializeSdk();
-
-	static void PopulateFilterManager();
-
-private:
-	Initialization() {}
-
+	void InitializeSdk();
+	void PopulateFilterManager();
 };
 
 
diff --git a/ePub3/_config.h b/ePub3/_config.h
index 10932d24b..d2a559cc5 100644
--- a/ePub3/_config.h
+++ b/ePub3/_config.h
@@ -152,6 +152,7 @@ typedef signed long ssize_t;
 # endif
 #endif
 
+#if !EPUB_PLATFORM(WINRT)
 #if EPUB_COMPILER(MSVC)
 # pragma section(".CRT$XCU",read)
 # define INITIALIZER(f) \
@@ -163,7 +164,7 @@ typedef signed long ssize_t;
     static void f(void) __attribute__((constructor)); \
     static void f(void)
 #endif
-
+#endif
 // MSVC doesn't have this macro
 #ifndef __PRETTY_FUNCTION__
 # define __PRETTY_FUNCTION__ __FUNCTION__
diff --git a/ePub3/utilities/run_loop.h b/ePub3/utilities/run_loop.h
index f59e3a595..5f7695200 100644
--- a/ePub3/utilities/run_loop.h
+++ b/ePub3/utilities/run_loop.h
@@ -507,17 +507,21 @@ class RunLoop : public PointerType<RunLoop>
     EPUB3_EXPORT
     void            WakeUp();
     
+# if EPUB_OS(WINDOWS) && EPUB_PLATFORM(WINRT)
+	static void InitRunLoopTLSKey();
+	static void KillRunLoopTLSKey();
+# endif
+
 protected:
     ///
     /// Internal Run function which takes an explicit timeout duration type.
     EPUB3_EXPORT
     ExitReason      RunInternal(bool returnAfterSourceHandled, std::chrono::nanoseconds& timeout);
     
-    
     ///
     /// Obtains the run loop for the current thread.
     EPUB3_EXPORT    RunLoop();
-    
+
 private:
     ///
     /// No copy constructor
@@ -579,6 +583,11 @@ class RunLoop : public PointerType<RunLoop>
     std::atomic<bool>                   _stop;
     std::atomic<bool>                   _resetHandles;
     Observer::Activity                  _observerMask;
+
+
+# if EPUB_PLATFORM(WINRT)
+	static DWORD RunLoopTLSKey;
+# endif
 #else
     shared_list<Timer>                  _timers;
     shared_list<Observer>               _observers;
diff --git a/ePub3/utilities/run_loop_common.ipp b/ePub3/utilities/run_loop_common.ipp
index 7dd3c93cf..266cb43a4 100644
--- a/ePub3/utilities/run_loop_common.ipp
+++ b/ePub3/utilities/run_loop_common.ipp
@@ -41,12 +41,13 @@ using namespace ThreadEmulation;
 #endif
 
 EPUB3_BEGIN_NAMESPACE
-
-#if EPUB_OS(WINDOWS)
-#ifndef TLS_OUT_OF_INDEXES
+#if EPUB_OS(WINDOWS) 
+# if !EPUB_PLATFORM(WINRT)
+# ifndef TLS_OUT_OF_INDEXES
 # define TLS_OUT_OF_INDEXES ((DWORD)0xffffffff)
-#endif
+# endif
 DWORD RunLoopTLSKey = TLS_OUT_OF_INDEXES;
+# endif
 #else
 static pthread_key_t RunLoopTLSKey;
 #endif
@@ -58,6 +59,8 @@ static void _DestroyTLSRunLoop(void* data)
     delete p;
 }
 #endif
+
+# if !EPUB_PLATFORM(WINRT)
 static void KillRunLoopTLSKey()
 {
 #if EPUB_OS(WINDOWS)
@@ -67,6 +70,7 @@ static void KillRunLoopTLSKey()
     pthread_key_delete(RunLoopTLSKey);
 #endif
 }
+
 INITIALIZER(InitRunLoopTLSKey)
 {
 #if EPUB_OS(WINDOWS)
@@ -81,6 +85,7 @@ INITIALIZER(InitRunLoopTLSKey)
     pthread_key_create(&RunLoopTLSKey, _DestroyTLSRunLoop);
 #endif
 }
+#endif
 
 RunLoopPtr RunLoop::CurrentRunLoop()
 {
diff --git a/ePub3/utilities/run_loop_windows.cpp b/ePub3/utilities/run_loop_windows.cpp
index 998682817..b85730650 100644
--- a/ePub3/utilities/run_loop_windows.cpp
+++ b/ePub3/utilities/run_loop_windows.cpp
@@ -794,4 +794,26 @@ void RunLoop::Timer::SetNextFireDateDuration(Clock::duration& when)
 #endif
 }
 
+#if EPUB_PLATFORM(WINRT)
+
+DWORD RunLoop::RunLoopTLSKey = TLS_OUT_OF_INDEXES;
+
+void RunLoop::KillRunLoopTLSKey() {
+	if (RunLoop::RunLoopTLSKey != TLS_OUT_OF_INDEXES) {
+		TlsFree(RunLoop::RunLoopTLSKey);
+	}
+}
+
+void RunLoop::InitRunLoopTLSKey() {
+	RunLoopTLSKey = TlsAlloc();
+	if (RunLoopTLSKey == TLS_OUT_OF_INDEXES)
+	{
+		OutputDebugString(L"No TLS Indexes for RunLoop!\n");
+		std::terminate();
+	}
+	atexit(RunLoop::KillRunLoopTLSKey);
+}
+
+#endif
+
 EPUB3_END_NAMESPACE