diff --git a/win32/genversion.bat b/win32/genversion.bat
index 9bc6917f29606f4b183edec3459c030297ac09e8..3a3d7cde59f747705705302d3fc755e1c51ad6e8 100644
--- a/win32/genversion.bat
+++ b/win32/genversion.bat
@@ -1,10 +1,38 @@
 @echo off
 
+setlocal enableextensions enabledelayedexpansion
+
 for /f %%v in ('git describe --tags --match "v*"') do set version=%%v
 
+if not "%version%"=="" goto :gotversion
+
+if exist "%~dp0..\version.mk" goto :getversion
+
+echo Git cannot be found, nor can version.mk. Generating unknown version.
+
+set version=unknown
+
+goto :gotversion
+
+:getversion
+
+for /f "delims== tokens=2" %%v in (%~dp0..\version.mk) do set version=%%v
+
+set version=!version:^"=!
+set version=!version: =!
+
+:gotversion
+
 set version_out=#define %2 "%version%"
+set version_mk=%2 = "%version%"
+
+echo %version_out%> %1_temp
+
+if %version%==unknown goto :skipgenerate
+
+echo %version_mk%> "%~dp0..\version.mk"
 
-echo %version_out% > %1_temp
+:skipgenerate
 
 echo n | comp %1_temp %1 > NUL 2> NUL