diff --git a/installer/win/installer.nsi b/installer/win/installer.nsi
index 1cca8b9..09ec0db 100644
--- a/installer/win/installer.nsi
+++ b/installer/win/installer.nsi
@@ -5,7 +5,9 @@
 ;--------------------------------------------------------
 
 ; Options
-!define Version "0.9.20"
+!ifndef Version
+    !define /ifndef Version "0.9.21"
+!endif
 !define DubExecPath "..\..\bin"
 
 ;--------------------------------------------------------
diff --git a/installer/win/make_installer.cmd b/installer/win/make_installer.cmd
new file mode 100644
index 0000000..943d94c
--- /dev/null
+++ b/installer/win/make_installer.cmd
@@ -0,0 +1,3 @@
+set GITVER=unknown
+for /f %%i in ('git describe') do set GITVER=%%i
+"%ProgramFiles(x86)%\NSIS\makensis.exe" "/DVersion=%GITVER:~1%" installer.nsi