diff --git a/Docs/src/attributes.but b/Docs/src/attributes.but
index 9682cefe..c45d11cf 100644
--- a/Docs/src/attributes.but
+++ b/Docs/src/attributes.but
@@ -291,9 +291,9 @@ See \W{http://msdn.microsoft.com/en-us/library/dd464660}{MSDN} for more informat
 
 \S2{amanifestsupportedos} ManifestSupportedOS
 
-\c none|all|WinVista|\\<b\\>Win7|Win8\\</b\\>|{GUID} [...]
+\c none|all|WinVista|\\<b\\>Win7|Win8|Win8.1\\</b\\>|{GUID} [...]
 
-Declare that the installer is compatible with the specified Windows version(s). This adds a SupportedOS entry in the compatibility section of the application manifest. The default list of Win7+Win8 will probably be updated to include newer Windows versions in the future. \e{none} is the default if \R{arequestexecutionlevel}{RequestExecutionLevel} is set to \e{none} for compatibility reasons.
+Declare that the installer is compatible with the specified Windows version(s). This adds a SupportedOS entry in the compatibility section of the application manifest. The default list of Win7+Win8+Win8.1 will probably be updated to include newer Windows versions in the future. \e{none} is the default if \R{arequestexecutionlevel}{RequestExecutionLevel} is set to \e{none} for compatibility reasons.
 
 You can read more about the changes in behavior on \W{http://msdn.microsoft.com/en-us/library/windows/desktop/hh848036}{MSDN}.
 
diff --git a/Docs/src/history.but b/Docs/src/history.but
index ff441570..af8b9d9d 100644
--- a/Docs/src/history.but
+++ b/Docs/src/history.but
@@ -10,6 +10,8 @@ Released on ?, 2013
 
 \b Default verbosity is /V3 without logo, MakeNSISW still uses /V4.
 
+\b \R{amanifestsupportedos}{ManifestSupportedOS} added support for the Windows 8.1 Preview GUID and it is set by default to avoid GetVersionEx compatibility behavior.
+
 \S2{} Minor Changes
 
 \b Fixed !finalize %1
diff --git a/Source/manifest.cpp b/Source/manifest.cpp
index c7aade2e..59972b75 100644
--- a/Source/manifest.cpp
+++ b/Source/manifest.cpp
@@ -57,6 +57,7 @@ bool SupportedOSList::append(const TCHAR* osid)
   else if (!_tcsicmp(osid,_T("WinVista"))) guid = _T("{e2011457-1546-43c5-a5fe-008deee3d3f0}");
   else if (!_tcsicmp(osid,_T("Win7"))) guid = _T("{35138b9a-5d96-4fbd-8e2d-a2440225f93a}");
   else if (!_tcsicmp(osid,_T("Win8"))) guid = _T("{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}");
+  else if (!_tcsicmp(osid,_T("Win8.1"))) guid = _T("{1f676c76-80e1-4239-95bb-83d0f6d0da78}");
 
   if (guid)
   {
diff --git a/Source/manifest.h b/Source/manifest.h
index 57045624..3bcb79bf 100644
--- a/Source/manifest.h
+++ b/Source/manifest.h
@@ -71,12 +71,14 @@ namespace manifest
       append(_T("WinVista"));
       append(_T("Win7"));
       append(_T("Win8"));
+      append(_T("Win8.1"));
     }
     void setdefault()
     {
       m_list.deleteall();
       append(_T("Win7"));
       append(_T("Win8"));
+      append(_T("Win8.1")); // In the default list because GetVersion(Ex) supposedly lies if this is not set in the manifest
       m_isdefaultlist = true;
     }
   };
diff --git a/Source/tokens.cpp b/Source/tokens.cpp
index c7c5713d..08fbbc9a 100644
--- a/Source/tokens.cpp
+++ b/Source/tokens.cpp
@@ -241,7 +241,7 @@ static tokenType tokenlist[TOK__LAST] =
 {TOK_XPSTYLE, _T("XPStyle"),1,0,_T("(on|off)"),TP_GLOBAL},
 {TOK_REQEXECLEVEL, _T("RequestExecutionLevel"),1,0,_T("none|user|highest|admin"),TP_GLOBAL},
 {TOK_MANIFEST_DPIAWARE,_T("ManifestDPIAware"),1,0,_T("notset|true|false"),TP_GLOBAL},
-{TOK_MANIFEST_SUPPORTEDOS,_T("ManifestSupportedOS"),1,-1,_T("none|all|WinVista|Win7|Win8|{GUID} [...]"),TP_GLOBAL},
+{TOK_MANIFEST_SUPPORTEDOS,_T("ManifestSupportedOS"),1,-1,_T("none|all|WinVista|Win7|Win8|Win8.1|{GUID} [...]"),TP_GLOBAL},
 {TOK_P_PACKEXEHEADER,_T("!packhdr"),2,0,_T("temp_file_name command_line_to_compress_that_temp_file"),TP_ALL},
 {TOK_P_FINALIZE,_T("!finalize"),1,0,_T("command_with_%1"),TP_ALL},
 {TOK_P_SYSTEMEXEC,_T("!system"),1,2,_T("command [<|>|<>|=) retval]"),TP_ALL},