diff --git a/plugin/fugitive.vim b/plugin/fugitive.vim
index 1d83f6c..3e29514 100644
--- a/plugin/fugitive.vim
+++ b/plugin/fugitive.vim
@@ -224,6 +224,9 @@ function! s:ProjectionistDetect() abort
     let base = FugitiveTreeForGitDir(dir)
   endif
   if len(base)
+    if exists('+shellslash') && !&shellslash
+      let base = tr(base, '/', '\')
+    endif
     call projectionist#append(base, FugitiveCommonDir(dir) . '/info/projections.json')
   endif
 endfunction