diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index c942188..c9e06ab 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -6409,7 +6409,7 @@ function! s:SquashArgument(...) abort
   if &filetype == 'fugitive'
     let commit = matchstr(getline('.'), '^\%(\%(\x\x\x\)\@!\l\+\s\+\)\=\zs[0-9a-f]\{4,\}\ze \|^' . s:ref_header . ': \zs\S\+')
   elseif has_key(s:temp_files, s:cpath(expand('%:p')))
-    let commit = matchstr(getline('.'), '\<\x\{4,\}\>')
+    let commit = matchstr(getline('.'), '\S\@<!\x\{4,\}\>')
   else
     let commit = s:Owner(@%)
   endif