diff --git a/ftplugin/markdown.vim b/ftplugin/markdown.vim
index 5e402269..1695a56f 100644
--- a/ftplugin/markdown.vim
+++ b/ftplugin/markdown.vim
@@ -377,7 +377,7 @@ function! s:Toc(...)
             endif
         endif
         " indent header based on level
-        let l:text = repeat('  ', h.level-1) . h.text
+        let l:text = h.level . '# ' . h.text
         " keep track of the longest header size (heading level + title)
         let l:total_len = strdisplaywidth(l:text)
         if l:total_len > l:header_max_len
@@ -405,14 +405,6 @@ function! s:Toc(...)
     else
         lopen
     endif
-    setlocal modifiable
-    for i in range(1, line('$'))
-        " this is the location-list data for the current item
-        let d = getloclist(0)[i-1]
-        call setline(i, d.text)
-    endfor
-    setlocal nomodified
-    setlocal nomodifiable
     execute 'normal! ' . l:cursor_header . 'G'
 endfunction
 
diff --git a/test/folding-toc.vader b/test/folding-toc.vader
index 8d688f77..026e0056 100644
--- a/test/folding-toc.vader
+++ b/test/folding-toc.vader
@@ -121,28 +121,28 @@ Execute (check TOC):
   let res = getloclist(0)
   let elem = res[0]
   AssertEqual elem.lnum, 1
-  AssertEqual elem.text, 'chap 1'
+  AssertEqual elem.text, '1# chap 1'
   let elem = res[1]
   AssertEqual elem.lnum, 15
-  AssertEqual elem.text, '  chap 1.1'
+  AssertEqual elem.text, '2# chap 1.1'
   let elem = res[2]
   AssertEqual elem.lnum, 25
-  AssertEqual elem.text, '    chap 1.1.1'
+  AssertEqual elem.text, '3# chap 1.1.1'
   let elem = res[3]
   AssertEqual elem.lnum, 30
-  AssertEqual elem.text, 'chap 2'
+  AssertEqual elem.text, '1# chap 2'
   let elem = res[4]
   AssertEqual elem.lnum, 34
-  AssertEqual elem.text, '  chap 2.1'
+  AssertEqual elem.text, '2# chap 2.1'
   let elem = res[5]
   AssertEqual elem.lnum, 41
-  AssertEqual elem.text, 'chap 3'
+  AssertEqual elem.text, '1# chap 3'
   let elem = res[6]
   AssertEqual elem.lnum, 45
-  AssertEqual elem.text, 'chap 4'
+  AssertEqual elem.text, '1# chap 4'
   let elem = res[7]
   AssertEqual elem.lnum, 50
-  AssertEqual elem.text, '  chap 4.1'
+  AssertEqual elem.text, '2# chap 4.1'
 
 Given markdown;
 ---
@@ -175,5 +175,5 @@ Execute (check Toc of yaml front matter):
   AssertEqual len(res), 1
   let elem = res[0]
   AssertEqual elem.lnum, 8
-  AssertEqual elem.text, '  heading'
+  AssertEqual elem.text, '2# heading'
   unlet g:vim_markdown_frontmatter
diff --git a/test/toc-autofit.vader b/test/toc-autofit.vader
index 26789975..29fc433a 100644
--- a/test/toc-autofit.vader
+++ b/test/toc-autofit.vader
@@ -45,9 +45,9 @@ Execute (toc window autofit width):
   :Toc
   let real_width = winwidth(0)
   :lclose
-  let expected_width = len(line) + 2*5 + 1 + 3 - 7
+  let expected_width = len(line) - len(matchstr(line, '^#\+ *')) + 1 + 3 + len('N# ')
   AssertEqual real_width, expected_width
   set nonumber
-" 2 spaces * 5 additional header levels + 1 space for first header +
-" 3 spaces for line numbers - 7 chars ('###### ') that don't show up on the TOC
+" 1 space for first header + 3 spaces for line numbers.
+" 7 chars ('###### ') are removed, and 3 char `N# ` are added.
 
diff --git a/test/toc.vader b/test/toc.vader
index 51269526..0797dcba 100644
--- a/test/toc.vader
+++ b/test/toc.vader
@@ -28,11 +28,14 @@ test
 
 Execute (Toc setex headers):
   :Toc
+  :setl modifiable
+  :%s/\m^\([^|]*|\)\{2} //
+  :setl nomodifiable nomodified
 
 Expect (setex headers):
-  header 1
-    header 2
-      header 3
+  1# header 1
+  2# header 2
+  3# header 3
 
 Given markdown;
 # header 1
@@ -49,11 +52,14 @@ test
 
 Execute (Toc atx headers):
   :Toc
+  :setl modifiable
+  :%s/\m^\([^|]*|\)\{2} //
+  :setl nomodifiable nomodified
 
 Expect (atx headers):
-  header 1
-    header 2
-      header 3
+  1# header 1
+  2# header 2
+  3# header 3
 
 Given markdown;
 ATX tests.
@@ -135,34 +141,37 @@ setex h2
 
 Execute (Toc multiple headers):
   :Toc
+  :setl modifiable
+  :%s/\m^\([^|]*|\)\{2} //
+  :setl nomodifiable nomodified
 
 Expect (multiple headers):
-  h1 space
-  h1 nospace
-  h1 2 spaces
-  h1 trailing hash
-    h2 space
-    h2 nospace
-    h2 trailing hash
-      h3 space
-      h3 nospace
-      h3 trailing hash
-        h4
-          h5
-            h6
-  h1 before h2
-    h2 between h1s
-  h1 after h2
-  setex h1
-    setex h2
-  setex h1 single punctuation
-  setex h1 punctuation longer than header
-  setex h1 before atx
-    atx h2
-      atx h3
-  atx h1
-    setex h2
-      atx h3 2
+  1# h1 space
+  1# h1 nospace
+  1# h1 2 spaces
+  1# h1 trailing hash
+  2# h2 space
+  2# h2 nospace
+  2# h2 trailing hash
+  3# h3 space
+  3# h3 nospace
+  3# h3 trailing hash
+  4# h4
+  5# h5
+  6# h6
+  1# h1 before h2
+  2# h2 between h1s
+  1# h1 after h2
+  1# setex h1
+  2# setex h2
+  1# setex h1 single punctuation
+  1# setex h1 punctuation longer than header
+  1# setex h1 before atx
+  2# atx h2
+  3# atx h3
+  1# atx h1
+  2# setex h2
+  3# atx h3 2
 
 Execute:
   :lclose