diff --git a/Include/Win/WinDef.nsh b/Include/Win/WinDef.nsh
index 14ee768b..8e23f6a5 100644
--- a/Include/Win/WinDef.nsh
+++ b/Include/Win/WinDef.nsh
@@ -41,8 +41,8 @@ IntOp ${_outvar} "${_in}" & 0xFFFF
 !define LOWORD "!insertmacro _Win_LOWORD "
 
 !macro _Win_HIWORD _outvar _in
-IntOp ${outvar} "${_in}" >> 16 ;sign extended :(
-${LOWORD} ${_outvar} ${outvar} ;make sure we strip off the upper word
+IntOp ${_outvar} "${_in}" >> 16 ;sign extended :(
+${LOWORD} ${_outvar} ${_outvar} ;make sure we strip off the upper word
 !macroend
 !define HIWORD "!insertmacro _Win_HIWORD "