diff --git a/dlls/kernelx/Exports.def b/dlls/kernelx/Exports.def
index 17adbb8..24f55c8 100644
--- a/dlls/kernelx/Exports.def
+++ b/dlls/kernelx/Exports.def
@@ -43,6 +43,7 @@ EXPORTS
 	InitializeConditionVariable	= NTDDLL.RtlInitializeConditionVariable @269
 	InitializeCriticalSection = NTDLL.RtlInitializeCriticalSection	@271
 	InitializeCriticalSectionAndSpinCount = InitializeCriticalSectionAndSpinCount_X @272
+	InitializeCriticalSectionEx = InitializeCriticalSectionEx_X @273
 	InitializeSListHead		= NTDLL.RtlInitializeSListHead	@275
 	InitializeSRWLock		= NTDLL.InitializeSRWLock				@276
 	IsDebuggerPresent		= IsDebuggerPresent_X			@283
diff --git a/dlls/kernelx/kernelx.cpp b/dlls/kernelx/kernelx.cpp
index 8378d1e..8a0b391 100644
--- a/dlls/kernelx/kernelx.cpp
+++ b/dlls/kernelx/kernelx.cpp
@@ -67,6 +67,11 @@ BOOL XMemFree_X(PVOID P, UINT64 a2)
     return off_18002B1B0(P, a2);*/
 }
 
+BOOL InitializeCriticalSectionEx_X(LPCRITICAL_SECTION lpCriticalSection, DWORD dwSpinCount, DWORD Flags)
+{
+    return InitializeCriticalSectionEx(lpCriticalSection, dwSpinCount, Flags);
+}
+
 LPTOP_LEVEL_EXCEPTION_FILTER SetUnhandledExceptionFilter_X(LPTOP_LEVEL_EXCEPTION_FILTER lpTopLevelExceptionFilter)
 {
     return SetUnhandledExceptionFilter(lpTopLevelExceptionFilter);
diff --git a/dlls/kernelx/kernelx.h b/dlls/kernelx/kernelx.h
index 77336a6..0a6f24e 100644
--- a/dlls/kernelx/kernelx.h
+++ b/dlls/kernelx/kernelx.h
@@ -90,6 +90,8 @@ extern "C" BOOL IsDebuggerPresent_X();
 
 extern "C" BOOL InitializeCriticalSectionAndSpinCount_X(LPCRITICAL_SECTION lpCriticalSection, DWORD dwSpinCount);
 
+extern "C" BOOL InitializeCriticalSectionEx_X(LPCRITICAL_SECTION lpCriticalSection, DWORD dwSpinCount, DWORD Flags);
+
 extern "C" GEOID GetUserGeoID_X(GEOCLASS GeoClass);
 
 extern "C" int GetUserDefaultLocaleName_X(LPWSTR lpLocaleName, int cchLocaleName);