diff --git a/Sources/Plasma/Apps/plClient/winmain.cpp b/Sources/Plasma/Apps/plClient/winmain.cpp
index 29e327e4..4d086bfe 100644
--- a/Sources/Plasma/Apps/plClient/winmain.cpp
+++ b/Sources/Plasma/Apps/plClient/winmain.cpp
@@ -46,7 +46,7 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 #include <stdio.h>
 #include <direct.h>     // windows directory handling fxns (for chdir)
 #include <process.h>
-#include <Shellapi.h>   // ShellExecuteA
+#include <shellapi.h>   // ShellExecuteA
 
 //#define DETACH_EXE  // Microsoft trick to force loading of exe to memory 
 #ifdef DETACH_EXE
diff --git a/Sources/Plasma/CoreLib/hsWindows.h b/Sources/Plasma/CoreLib/hsWindows.h
index e1b50c39..2bafc8f1 100644
--- a/Sources/Plasma/CoreLib/hsWindows.h
+++ b/Sources/Plasma/CoreLib/hsWindows.h
@@ -63,7 +63,7 @@ You can contact Cyan Worlds, Inc. by email legal@cyan.com
 
 #   define NOMINMAX
 #   define WIN32_LEAN_AND_MEAN
-#   include <Windows.h>
+#   include <windows.h>
 #   include <ws2tcpip.h> // Pulls in WinSock 2 for us
 
     // This needs to be after #include <windows.h>, since it also includes windows.h
diff --git a/Sources/Plasma/PubUtilLib/plAudio/plEAXEffects.h b/Sources/Plasma/PubUtilLib/plAudio/plEAXEffects.h
index 1f465b12..d5c68c46 100644
--- a/Sources/Plasma/PubUtilLib/plAudio/plEAXEffects.h
+++ b/Sources/Plasma/PubUtilLib/plAudio/plEAXEffects.h
@@ -68,7 +68,7 @@ typedef struct _EAXREVERBPROPERTIES EAXREVERBPROPERTIES;
 #if HS_BUILD_FOR_WIN32
     typedef struct _GUID GUID;
 #else
-#    define GUID char*
+    typedef char* GUID;
 #endif
 
 class plEAXListener