diff --git a/plug.vim b/plug.vim
index 4a606f0..9cb02f7 100644
--- a/plug.vim
+++ b/plug.vim
@@ -288,8 +288,9 @@ function! s:version_requirement(val, min)
 endfunction
 
 function! s:git_version_requirement(...)
-  let s:git_version = get(s:, 'git_version',
-    \ map(split(split(s:system('git --version'))[-1], '\.'), 'str2nr(v:val)'))
+  if !exists('s:git_version')
+    let s:git_version = map(split(split(s:system('git --version'))[-1], '\.'), 'str2nr(v:val)')
+  endif
   return s:version_requirement(s:git_version, a:000)
 endfunction