diff --git a/autoload/vimwiki/base.vim b/autoload/vimwiki/base.vim
index 0e812ef..ee5f7a8 100644
--- a/autoload/vimwiki/base.vim
+++ b/autoload/vimwiki/base.vim
@@ -2276,7 +2276,7 @@ endfunction
 
 function! vimwiki#base#detect_nested_syntax() abort
   let last_word = '\v.*<(\w+)\s*$'
-  let lines = map(filter(getline(1, '$'), 'v:val =~# "\\%({{{\\|```\\)" && v:val =~# last_word'),
+  let lines = map(filter(getline(1, '$'), 'v:val =~# "\\%({{{\\|`\\{3,\}\\|\\~\\{3,\}\\)" && v:val =~# last_word'),
         \ 'substitute(v:val, last_word, "\\=submatch(1)", "")')
   let dict = {}
   for elem in lines
diff --git a/doc/vimwiki.txt b/doc/vimwiki.txt
index 292d6bd..796048e 100644
--- a/doc/vimwiki.txt
+++ b/doc/vimwiki.txt
@@ -3486,6 +3486,8 @@ https://github.com/vimwiki-backup/vimwiki/issues.
 2.5 (in progress)~
 
 New:~
+    * Issue #764: fenced code blocks are properly supported for markdown
+      syntax i.e. more than 3 backticks, adds tilde support.
     * Set default |vimwiki-option-list_margin| = 0 for markdown syntax.
     * PR #785: |:VimwikiGoto| completion works with part of filename and
       nested directories
diff --git a/syntax/vimwiki_markdown.vim b/syntax/vimwiki_markdown.vim
index e68661a..51896b0 100644
--- a/syntax/vimwiki_markdown.vim
+++ b/syntax/vimwiki_markdown.vim
@@ -80,8 +80,8 @@ let s:markdown_syntax.list_markers = ['-', '*', '+', '1.']
 let s:markdown_syntax.rxListDefine = '::\%(\s\|$\)'
 
 " Preformatted text
-let s:markdown_syntax.rxPreStart = '```'
-let s:markdown_syntax.rxPreEnd = '```'
+let s:markdown_syntax.rxPreStart = '\%(`\{3,}\|\~\{3,}\)'
+let s:markdown_syntax.rxPreEnd = '\%(`\{3,}\|\~\{3,}\)'
 
 " Math block
 let s:markdown_syntax.rxMathStart = '\$\$'
diff --git a/test/syntax.vader b/test/syntax.vader
index ca22ce6..3cfe860 100644
--- a/test/syntax.vader
+++ b/test/syntax.vader
@@ -211,6 +211,21 @@ Given vimwiki (Markdown, Text and Vim):
   set hlsearch
   ```
 
+  `````vim
+  " this is vim
+  set hlsearch
+  `````
+
+  ~~~vim
+  " this is vim
+  set hlsearch
+  ~~~
+
+  ~~~~~vim
+  " this is vim
+  set hlsearch
+  ~~~~~~~~~~~
+
 Execute (Set syntax markdown):
   let g:vimwiki_global_vars['vimwiki_automatic_nested_syntaxes'] = 1
   call SetSyntax('markdown')
@@ -225,6 +240,18 @@ Execute (Assert Code syntax):
   AssertEqual SyntaxAt(5, 1), 'VimwikiPre'
   AssertEqual SyntaxAt(9, 1), 'vimLineComment'
   AssertEqual SyntaxAt(10, 1), 'vimCommand'
+  AssertEqual SyntaxAt(13, 1), 'VimwikiPre'
+  AssertEqual SyntaxAt(14, 1), 'vimLineComment'
+  AssertEqual SyntaxAt(15, 1), 'vimCommand'
+  AssertEqual SyntaxAt(16, 1), 'VimwikiPre'
+  AssertEqual SyntaxAt(18, 1), 'VimwikiPre'
+  AssertEqual SyntaxAt(19, 1), 'vimLineComment'
+  AssertEqual SyntaxAt(20, 1), 'vimCommand'
+  AssertEqual SyntaxAt(21, 1), 'VimwikiPre'
+  AssertEqual SyntaxAt(23, 1), 'VimwikiPre'
+  AssertEqual SyntaxAt(24, 1), 'vimLineComment'
+  AssertEqual SyntaxAt(25, 1), 'vimCommand'
+  AssertEqual SyntaxAt(26, 1), 'VimwikiPre'
 
 
 # 11 Math {{{1
@@ -277,7 +304,7 @@ Given vimwiki (Math wiki):
   &= 2.
   }}$
 
-Execute (Set syntax markdown):
+Execute (Set syntax default):
   call SetSyntax('default')
 
 Execute (Assert math syntax):