diff --git a/library/mapiStubLibrary.cpp b/library/mapiStubLibrary.cpp
index a228a01..28e0af1 100644
--- a/library/mapiStubLibrary.cpp
+++ b/library/mapiStubLibrary.cpp
@@ -1,5 +1,5 @@
 #define _WINSOCKAPI_
-#include <Windows.h>
+#include <windows.h>
 
 #ifdef WIN_NOEXCEPT
 #undef WIN_NOEXCEPT
@@ -17,7 +17,7 @@
 #include <MAPIVal.h>
 #include <MAPISPI.h>
 #include <IMessage.h>
-#include <TNEF.h>
+#include <tnef.h>
 
 // clang-format off
 #pragma warning(disable : 26426) // Warning C26426 Global initializer calls a non-constexpr (i.22)
@@ -2747,4 +2747,4 @@ DEFINE_STUB_FUNCTION_5(
 	LPMAPIUID,
 	ULONG*,
 	LPENTRYID*,
-	MAPI_E_CALL_FAILED)
\ No newline at end of file
+	MAPI_E_CALL_FAILED)
diff --git a/library/stubutils.cpp b/library/stubutils.cpp
index 69093a2..bd00dce 100644
--- a/library/stubutils.cpp
+++ b/library/stubutils.cpp
@@ -4,7 +4,7 @@
 #include <algorithm>
 #include <iterator>
 #include <MAPIX.h>
-#include <Msi.h>
+#include <msi.h>
 
 // clang-format off
 #pragma warning(disable : 26426) // Warning C26426 Global initializer calls a non-constexpr (i.22)