diff --git a/plug.vim b/plug.vim
index e8ca48b..198aaa0 100644
--- a/plug.vim
+++ b/plug.vim
@@ -2013,10 +2013,24 @@ function! s:git_validate(spec, check_branch)
               \ branch, a:spec.branch)
       endif
       if empty(err)
-        let commits = len(s:lines(s:system(printf('git rev-list origin/%s..HEAD', a:spec.branch), a:spec.dir)))
-        if !v:shell_error && commits
-          let err = join([printf('Diverged from origin/%s by %d commit(s).', a:spec.branch, commits),
-                        \ 'Reinstall after PlugClean.'], "\n")
+        let [ahead, behind] = split(s:lastline(s:system(printf(
+              \ 'git rev-list --count --left-right HEAD...origin/%s',
+              \ a:spec.branch), a:spec.dir)), '\t')
+        if !v:shell_error && ahead
+          if behind
+            let base_error = printf(
+                  \ 'Diverged from origin/%%s (%%d commit(s) ahead and %d commit(s) behind!', behind)
+          else
+            let base_error = 'Ahead of origin/%s by %d commit(s).'
+          endif
+          let err = join([printf(base_error, a:spec.branch, ahead),
+                \ 'Can you push it yourself?',
+                \ 'Otherwise try reinstalling it after cleaning it manually.'], "\n")
+          " Only mention PlugClean if diverged, otherwise it's likely to be
+          " pushable (and probably not that messed up).
+          if behind
+            let err .= "\nTry PlugClean after backing it up."
+          endif
         endif
       endif
     endif