Index: CMake/VTKDetermineVersion.cmake
--- CMake/VTKDetermineVersion.cmake.orig
+++ CMake/VTKDetermineVersion.cmake
@@ -25,7 +25,7 @@ function(determine_version source_dir git_command var_
     # this function.
     return ()
   elseif (NOT VTK_GIT_DESCRIBE AND
-          EXISTS ${git_command} AND
+          EXISTS "${git_command}" AND
           EXISTS ${source_dir}/.git)
     execute_process(
       COMMAND ${git_command} describe
