diff --git a/src/Components/Modules/ClientCommand.cpp b/src/Components/Modules/ClientCommand.cpp
index 07fdbba1..a005cdca 100644
--- a/src/Components/Modules/ClientCommand.cpp
+++ b/src/Components/Modules/ClientCommand.cpp
@@ -246,7 +246,7 @@ namespace Components
 			if (ent->client->sess.sessionState != Game::SESS_STATE_PLAYING || !CheatsOk(ent))
 				return;
 
-			auto** bgs = Game::Sys::GetTls<Game::bgs_t*>(Game::Sys::ThreadOffset::LEVEL_BGS);
+			auto** bgs = Game::Sys::GetTls<Game::bgs_t*>(Game::Sys::TLS_OFFSET::LEVEL_BGS);
 
 			assert(*bgs == nullptr);
 
diff --git a/src/Game/Common.hpp b/src/Game/Common.hpp
index 85f296bd..012e5f07 100644
--- a/src/Game/Common.hpp
+++ b/src/Game/Common.hpp
@@ -77,16 +77,16 @@ namespace Game
 	extern const char* Com_LoadInfoString_FastFile(const char* fileName, const char* fileDesc, const char* ident, char* loadBuffer);
 }
 
-#define Com_InitThreadData()                                                   \
-{                                                                              \
-	static Game::ProfileStack profile_stack{};                                 \
-	static Game::va_info_t va_info{};                                          \
-	static jmp_buf g_com_error{};                                              \
-	static Game::TraceThreadInfo g_trace_thread_info{};                        \
-	static void* g_thread_values[Game::THREAD_VALUE_COUNT]{};                  \
-	*(Game::Sys::GetTls<void*>(Game::Sys::THREAD_VALUES)) = g_thread_values;   \
-	Game::Sys_SetValue(Game::THREAD_VALUE_PROF_STACK, &profile_stack);         \
-	Game::Sys_SetValue(Game::THREAD_VALUE_VA, &va_info);                       \
-	Game::Sys_SetValue(Game::THREAD_VALUE_COM_ERROR, &g_com_error);            \
-	Game::Sys_SetValue(Game::THREAD_VALUE_TRACE, &g_trace_thread_info);        \
+#define Com_InitThreadData()                                                             \
+{                                                                                        \
+	static Game::ProfileStack profile_stack{};                                           \
+	static Game::va_info_t va_info{};                                                    \
+	static jmp_buf g_com_error{};                                                        \
+	static Game::TraceThreadInfo g_trace_thread_info{};                                  \
+	static void* g_thread_values[Game::THREAD_VALUE_COUNT]{};                            \
+	*(Game::Sys::GetTls<void*>(Game::Sys::TLS_OFFSET::THREAD_VALUES)) = g_thread_values; \
+	Game::Sys_SetValue(Game::THREAD_VALUE_PROF_STACK, &profile_stack);                   \
+	Game::Sys_SetValue(Game::THREAD_VALUE_VA, &va_info);                                 \
+	Game::Sys_SetValue(Game::THREAD_VALUE_COM_ERROR, &g_com_error);                      \
+	Game::Sys_SetValue(Game::THREAD_VALUE_TRACE, &g_trace_thread_info);                  \
 }
diff --git a/src/Game/System.cpp b/src/Game/System.cpp
index b4943c4c..21148722 100644
--- a/src/Game/System.cpp
+++ b/src/Game/System.cpp
@@ -12,6 +12,7 @@ namespace Game
 	Sys_ListFiles_t Sys_ListFiles = Sys_ListFiles_t(0x45A660);
 	Sys_Milliseconds_t Sys_Milliseconds = Sys_Milliseconds_t(0x42A660);
 	Sys_Error_t Sys_Error = Sys_Error_t(0x43D570);
+	Sys_Sleep_t Sys_Sleep = Sys_Sleep_t(0x4169C0);
 	Sys_LockWrite_t Sys_LockWrite = Sys_LockWrite_t(0x435880);
 	Sys_TempPriorityAtLeastNormalBegin_t Sys_TempPriorityAtLeastNormalBegin = Sys_TempPriorityAtLeastNormalBegin_t(0x478680);
 	Sys_TempPriorityEnd_t Sys_TempPriorityEnd = Sys_TempPriorityEnd_t(0x4DCF00);
@@ -30,7 +31,7 @@ namespace Game
 	void Sys_LockRead(FastCriticalSection* critSect)
 	{
 		InterlockedIncrement(&critSect->readCount);
-		while (critSect->writeCount) std::this_thread::sleep_for(1ms);
+		while (critSect->writeCount) Sys_Sleep(1);
 	}
 
 	void Sys_UnlockRead(FastCriticalSection* critSect)
@@ -39,10 +40,16 @@ namespace Game
 		InterlockedDecrement(&critSect->readCount);
 	}
 
+	void Sys_UnlockWrite(FastCriticalSection* critSect)
+	{
+		assert(critSect->writeCount > 0);
+		InterlockedDecrement(&critSect->writeCount);
+		Sys_TempPriorityEnd(&critSect->tempPriority);
+	}
+
 	bool Sys_TryEnterCriticalSection(CriticalSection critSect)
 	{
-		assert(static_cast<unsigned int>(critSect) <
-			static_cast<unsigned int>(CRITSECT_COUNT));
+		AssertIn(critSect, CRITSECT_COUNT);
 
 		return TryEnterCriticalSection(&s_criticalSection[critSect]) != FALSE;
 	}
diff --git a/src/Game/System.hpp b/src/Game/System.hpp
index db6ce89f..5e3260f1 100644
--- a/src/Game/System.hpp
+++ b/src/Game/System.hpp
@@ -32,6 +32,9 @@ namespace Game
 	typedef int(*Sys_Milliseconds_t)();
 	extern Sys_Milliseconds_t Sys_Milliseconds;
 
+	typedef void(*Sys_Sleep_t)(int msec);
+	extern Sys_Sleep_t Sys_Sleep;
+
 	typedef void(*Sys_LockWrite_t)(FastCriticalSection* critSect);
 	extern Sys_LockWrite_t Sys_LockWrite;
 
@@ -68,13 +71,14 @@ namespace Game
 
 	extern void Sys_LockRead(FastCriticalSection* critSect);
 	extern void Sys_UnlockRead(FastCriticalSection* critSect);
+	extern void Sys_UnlockWrite(FastCriticalSection* critSect);
 
 	extern bool Sys_TryEnterCriticalSection(CriticalSection critSect);
 
 	class Sys
 	{
 	public:
-		enum ThreadOffset : unsigned int
+		enum class TLS_OFFSET : unsigned int
 		{
 			LEVEL_BGS = 0xC,
 			THREAD_VALUES = 0x14,
@@ -85,10 +89,10 @@ namespace Game
 		};
 
 		template <typename T>
-		static T* GetTls(ThreadOffset offset)
+		static T* GetTls(TLS_OFFSET offset)
 		{
 			const auto* tls = reinterpret_cast<std::uintptr_t*>(__readfsdword(0x2C));
-			return reinterpret_cast<T*>(tls[*g_dwTlsIndex] + offset);
+			return reinterpret_cast<T*>(tls[*g_dwTlsIndex] + static_cast<std::underlying_type_t<TLS_OFFSET>>(offset));
 		}
 	};
 }