diff --git a/_test/extra.txt b/_test/extra.txt
index 4f9499c..7c95ca4 100644
--- a/_test/extra.txt
+++ b/_test/extra.txt
@@ -159,3 +159,79 @@ bbb
 <img src="gt.jpg" alt="&gt;" />
 <img src="amp.jpg" alt="&amp;" /></p>
 //= = = = = = = = = = = = = = = = = = = = = = = =//
+
+
+13: fenced code block starting with tab inside list
+//- - - - - - - - -//
+* foo
+  ```Makefile
+  foo
+  	foo
+  ```
+//- - - - - - - - -//
+<ul>
+<li>foo
+<pre><code class="language-Makefile">foo
+	foo
+</code></pre>
+</li>
+</ul>
+//= = = = = = = = = = = = = = = = = = = = = = = =//
+
+14: fenced code block inside list, mismatched tab start
+//- - - - - - - - -//
+* foo
+  ```Makefile
+  foo
+ 	foo
+  ```
+//- - - - - - - - -//
+<ul>
+<li>foo
+<pre><code class="language-Makefile">foo
+  foo
+</code></pre>
+</li>
+</ul>
+//= = = = = = = = = = = = = = = = = = = = = = = =//
+
+
+15: fenced code block inside nested list
+//- - - - - - - - -//
+* foo
+  -  bar
+     ```Makefile
+     foo
+     	foo
+     ```
+//- - - - - - - - -//
+<ul>
+<li>foo
+<ul>
+<li>bar
+<pre><code class="language-Makefile">foo
+	foo
+</code></pre>
+</li>
+</ul>
+</li>
+</ul>
+//= = = = = = = = = = = = = = = = = = = = = = = =//
+
+16: indented code block starting with a tab.
+//- - - - - - - - -//
+* foo
+   
+      foo
+      	foo
+
+//- - - - - - - - -//
+<ul>
+<li>
+<p>foo</p>
+<pre><code>foo
+	foo
+</code></pre>
+</li>
+</ul>
+//= = = = = = = = = = = = = = = = = = = = = = = =//
diff --git a/parser/code_block.go b/parser/code_block.go
index d02c21f..8781bb0 100644
--- a/parser/code_block.go
+++ b/parser/code_block.go
@@ -49,6 +49,19 @@ func (b *codeBlockParser) Continue(node ast.Node, reader text.Reader, pc Context
 	}
 	reader.AdvanceAndSetPadding(pos, padding)
 	_, segment = reader.PeekLine()
+
+	// if code block line starts with a tab, keep a tab as it is.
+	if segment.Padding != 0 {
+		offsetWithPadding := reader.LineOffset()
+		sl, ss := reader.Position()
+		reader.SetPosition(sl, text.NewSegment(ss.Start-1, ss.Stop))
+		if offsetWithPadding == reader.LineOffset() {
+			segment.Padding = 0
+			segment.Start--
+		}
+		reader.SetPosition(sl, ss)
+	}
+
 	node.Lines().Append(segment)
 	reader.Advance(segment.Len() - 1)
 	return Continue | NoChildren
diff --git a/parser/fcode_block.go b/parser/fcode_block.go
index f5b83ee..75410d7 100644
--- a/parser/fcode_block.go
+++ b/parser/fcode_block.go
@@ -71,6 +71,17 @@ func (b *fencedCodeBlockParser) Open(parent ast.Node, reader text.Reader, pc Con
 func (b *fencedCodeBlockParser) Continue(node ast.Node, reader text.Reader, pc Context) State {
 	line, segment := reader.PeekLine()
 	fdata := pc.Get(fencedCodeBlockInfoKey).(*fenceData)
+	// if code block line starts with a tab, keep a tab as it is.
+	if segment.Padding != 0 {
+		offsetWithPadding := reader.LineOffset()
+		sl, ss := reader.Position()
+		reader.SetPosition(sl, text.NewSegment(ss.Start-1, ss.Stop))
+		if offsetWithPadding == reader.LineOffset() {
+			segment.Padding = 0
+			segment.Start--
+		}
+		reader.SetPosition(sl, ss)
+	}
 	w, pos := util.IndentWidth(line, reader.LineOffset())
 	if w < 4 {
 		i := pos