diff --git a/block_test.go b/block_test.go
index 5cbff6d..326c311 100644
--- a/block_test.go
+++ b/block_test.go
@@ -19,6 +19,7 @@ import (
 )
 
 func TestPrefixHeaderNoExtensions(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"# Header 1\n",
 		"<h1>Header 1</h1>\n",
@@ -88,6 +89,7 @@ func TestPrefixHeaderNoExtensions(t *testing.T) {
 }
 
 func TestPrefixHeaderSpaceExtension(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"# Header 1\n",
 		"<h1>Header 1</h1>\n",
@@ -148,6 +150,7 @@ func TestPrefixHeaderSpaceExtension(t *testing.T) {
 }
 
 func TestPrefixHeaderIdExtension(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"# Header 1 {#someid}\n",
 		"<h1 id=\"someid\">Header 1</h1>\n",
@@ -208,6 +211,7 @@ func TestPrefixHeaderIdExtension(t *testing.T) {
 }
 
 func TestPrefixHeaderIdExtensionWithPrefixAndSuffix(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"# header 1 {#someid}\n",
 		"<h1 id=\"PRE:someid:POST\">header 1</h1>\n",
@@ -260,6 +264,7 @@ func TestPrefixHeaderIdExtensionWithPrefixAndSuffix(t *testing.T) {
 }
 
 func TestPrefixAutoHeaderIdExtension(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"# Header 1\n",
 		"<h1 id=\"header-1\">Header 1</h1>\n",
@@ -311,6 +316,7 @@ func TestPrefixAutoHeaderIdExtension(t *testing.T) {
 }
 
 func TestPrefixAutoHeaderIdExtensionWithPrefixAndSuffix(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"# Header 1\n",
 		"<h1 id=\"PRE:header-1:POST\">Header 1</h1>\n",
@@ -372,6 +378,7 @@ func TestPrefixAutoHeaderIdExtensionWithPrefixAndSuffix(t *testing.T) {
 }
 
 func TestPrefixHeaderLevelOffset(t *testing.T) {
+	t.Parallel()
 	var offsetTests = []struct {
 		offset int
 		tests  []string
@@ -458,6 +465,7 @@ func TestPrefixHeaderLevelOffset(t *testing.T) {
 }
 
 func TestPrefixMultipleHeaderExtensions(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"# Header\n\n# Header {#header}\n\n# Header 1",
 		"<h1 id=\"header\">Header</h1>\n\n<h1 id=\"header-1\">Header</h1>\n\n<h1 id=\"header-1-1\">Header 1</h1>\n",
@@ -466,6 +474,7 @@ func TestPrefixMultipleHeaderExtensions(t *testing.T) {
 }
 
 func TestUnderlineHeaders(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"Header 1\n========\n",
 		"<h1>Header 1</h1>\n",
@@ -516,6 +525,7 @@ func TestUnderlineHeaders(t *testing.T) {
 }
 
 func TestUnderlineHeadersAutoIDs(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"Header 1\n========\n",
 		"<h1 id=\"header-1\">Header 1</h1>\n",
@@ -566,6 +576,7 @@ func TestUnderlineHeadersAutoIDs(t *testing.T) {
 }
 
 func TestHorizontalRule(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"-\n",
 		"<p>-</p>\n",
@@ -631,6 +642,7 @@ func TestHorizontalRule(t *testing.T) {
 }
 
 func TestUnorderedList(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"* Hello\n",
 		"<ul>\n<li>Hello</li>\n</ul>\n",
@@ -742,6 +754,7 @@ func TestUnorderedList(t *testing.T) {
 }
 
 func TestOrderedList(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"1. Hello\n",
 		"<ol>\n<li>Hello</li>\n</ol>\n",
@@ -838,6 +851,7 @@ func TestOrderedList(t *testing.T) {
 }
 
 func TestDefinitionList(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"Term 1\n:   Definition a\n",
 		"<dl>\n<dt>Term 1</dt>\n<dd>Definition a</dd>\n</dl>\n",
@@ -940,6 +954,7 @@ func TestDefinitionList(t *testing.T) {
 }
 
 func TestConsecutiveLists(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"1. Hello\n\n* Hello\n\nTerm 1\n:   Definition a\n",
 		"<ol>\n<li>Hello</li>\n</ol>\n\n<ul>\n<li>Hello</li>\n</ul>\n\n<dl>\n<dt>Term 1</dt>\n<dd>Definition a</dd>\n</dl>\n",
@@ -951,6 +966,7 @@ func TestConsecutiveLists(t *testing.T) {
 }
 
 func TestPreformattedHtml(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"<div></div>\n",
 		"<div></div>\n",
@@ -1004,6 +1020,7 @@ func TestPreformattedHtml(t *testing.T) {
 }
 
 func TestPreformattedHtmlLax(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"Paragraph\n<div>\nHere? >&<\n</div>\n",
 		"<p>Paragraph</p>\n\n<div>\nHere? >&<\n</div>\n",
@@ -1027,6 +1044,7 @@ func TestPreformattedHtmlLax(t *testing.T) {
 }
 
 func TestFencedCodeBlock(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"``` go\nfunc foo() bool {\n\treturn true;\n}\n```\n",
 		"<pre><code class=\"language-go\">func foo() bool {\n\treturn true;\n}\n</code></pre>\n",
@@ -1122,6 +1140,7 @@ func TestFencedCodeBlock(t *testing.T) {
 }
 
 func TestFencedCodeInsideBlockquotes(t *testing.T) {
+	t.Parallel()
 	cat := func(s ...string) string { return strings.Join(s, "\n") }
 	var tests = []string{
 		cat("> ```go",
@@ -1234,6 +1253,7 @@ okay
 }
 
 func TestTable(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"a | b\n---|---\nc | d\n",
 		"<table>\n<thead>\n<tr>\n<th>a</th>\n<th>b</th>\n</tr>\n</thead>\n\n" +
@@ -1281,6 +1301,7 @@ func TestTable(t *testing.T) {
 }
 
 func TestUnorderedListWith_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"* Hello\n",
 		"<ul>\n<li>Hello</li>\n</ul>\n",
@@ -1392,6 +1413,7 @@ func TestUnorderedListWith_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
 }
 
 func TestOrderedList_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"1. Hello\n",
 		"<ol>\n<li>Hello</li>\n</ol>\n",
@@ -1488,6 +1510,7 @@ func TestOrderedList_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
 }
 
 func TestFencedCodeBlock_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"``` go\nfunc foo() bool {\n\treturn true;\n}\n```\n",
 		"<pre><code class=\"language-go\">func foo() bool {\n\treturn true;\n}\n</code></pre>\n",
@@ -1562,6 +1585,7 @@ func TestFencedCodeBlock_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
 }
 
 func TestListWithFencedCodeBlock(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"1. one\n\n    ```\n    code\n    ```\n\n2. two\n",
 		"<ol>\n<li><p>one</p>\n\n<pre><code>code\n</code></pre></li>\n\n<li><p>two</p></li>\n</ol>\n",
@@ -1573,6 +1597,7 @@ func TestListWithFencedCodeBlock(t *testing.T) {
 }
 
 func TestListWithMalformedFencedCodeBlock(t *testing.T) {
+	t.Parallel()
 	// Ensure that in the case of an unclosed fenced code block in a list,
 	// no source gets ommitted (even if it is malformed).
 	// See russross/blackfriday#372 for context.
@@ -1587,6 +1612,7 @@ func TestListWithMalformedFencedCodeBlock(t *testing.T) {
 }
 
 func TestListWithFencedCodeBlockNoExtensions(t *testing.T) {
+	t.Parallel()
 	// If there is a fenced code block in a list, and FencedCode is not set,
 	// lists should be processed normally.
 	var tests = []string{
@@ -1600,6 +1626,7 @@ func TestListWithFencedCodeBlockNoExtensions(t *testing.T) {
 }
 
 func TestTitleBlock_EXTENSION_TITLEBLOCK(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"% Some title\n" +
 			"% Another title line\n" +
@@ -1614,6 +1641,7 @@ func TestTitleBlock_EXTENSION_TITLEBLOCK(t *testing.T) {
 }
 
 func TestBlockComments(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"Some text\n\n<!-- comment -->\n",
 		"<p>Some text</p>\n\n<!-- comment -->\n",
@@ -1628,6 +1656,7 @@ func TestBlockComments(t *testing.T) {
 }
 
 func TestTOC(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"# Title\n\n##Subtitle1\n\n##Subtitle2",
 		//"<nav>\n<ul>\n<li><a href=\"#toc_0\">Title</a>\n<ul>\n<li><a href=\"#toc_1\">Subtitle1</a></li>\n<li><a href=\"#toc_2\">Subtitle2</a></li>\n</ul></li>\n</ul>\n</nav>\n\n<h1 id=\"toc_0\">Title</h1>\n\n<h2 id=\"toc_1\">Subtitle1</h2>\n\n<h2 id=\"toc_2\">Subtitle2</h2>\n",
@@ -1748,6 +1777,7 @@ func TestTOC(t *testing.T) {
 }
 
 func TestCompletePage(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"*foo*",
 		`<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
@@ -1769,6 +1799,7 @@ func TestCompletePage(t *testing.T) {
 }
 
 func TestIsFenceLine(t *testing.T) {
+	t.Parallel()
 	tests := []struct {
 		data          []byte
 		infoRequested bool
diff --git a/esc_test.go b/esc_test.go
index ff67d54..fe318f7 100644
--- a/esc_test.go
+++ b/esc_test.go
@@ -6,6 +6,7 @@ import (
 )
 
 func TestEsc(t *testing.T) {
+	t.Parallel()
 	tests := []string{
 		"abc", "abc",
 		"a&c", "a&amp;c",
diff --git a/inline_test.go b/inline_test.go
index 69b70ae..5a91d8a 100644
--- a/inline_test.go
+++ b/inline_test.go
@@ -21,6 +21,7 @@ import (
 )
 
 func TestEmphasis(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"nothing inline\n",
 		"<p>nothing inline</p>\n",
@@ -77,6 +78,7 @@ func TestEmphasis(t *testing.T) {
 }
 
 func TestReferenceOverride(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"test [ref1][]\n",
 		"<p>test <a href=\"http://www.ref1.com/\" title=\"Reference 1\">ref1</a></p>\n",
@@ -135,6 +137,7 @@ func TestReferenceOverride(t *testing.T) {
 }
 
 func TestStrong(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"nothing inline\n",
 		"<p>nothing inline</p>\n",
@@ -194,6 +197,7 @@ func TestStrong(t *testing.T) {
 }
 
 func TestEmphasisMix(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"***triple emphasis***\n",
 		"<p><strong><em>triple emphasis</em></strong></p>\n",
@@ -223,6 +227,7 @@ func TestEmphasisMix(t *testing.T) {
 }
 
 func TestEmphasisLink(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"[first](before) *text[second] (inside)text* [third](after)\n",
 		"<p><a href=\"before\">first</a> <em>text<a href=\"inside\">second</a>text</em> <a href=\"after\">third</a></p>\n",
@@ -240,6 +245,7 @@ func TestEmphasisLink(t *testing.T) {
 }
 
 func TestStrikeThrough(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"nothing inline\n",
 		"<p>nothing inline</p>\n",
@@ -269,6 +275,7 @@ func TestStrikeThrough(t *testing.T) {
 }
 
 func TestCodeSpan(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"`source code`\n",
 		"<p><code>source code</code></p>\n",
@@ -307,6 +314,7 @@ func TestCodeSpan(t *testing.T) {
 }
 
 func TestLineBreak(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"this line  \nhas a break\n",
 		"<p>this line<br />\nhas a break</p>\n",
@@ -346,6 +354,7 @@ func TestLineBreak(t *testing.T) {
 }
 
 func TestInlineLink(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"[foo](/bar/)\n",
 		"<p><a href=\"/bar/\">foo</a></p>\n",
@@ -463,6 +472,7 @@ func TestInlineLink(t *testing.T) {
 }
 
 func TestRelAttrLink(t *testing.T) {
+	t.Parallel()
 	var nofollowTests = []string{
 		"[foo](http://bar.com/foo/)\n",
 		"<p><a href=\"http://bar.com/foo/\" rel=\"nofollow\">foo</a></p>\n",
@@ -521,6 +531,7 @@ func TestRelAttrLink(t *testing.T) {
 }
 
 func TestHrefTargetBlank(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		// internal link
 		"[foo](/bar/)\n",
@@ -550,6 +561,7 @@ func TestHrefTargetBlank(t *testing.T) {
 }
 
 func TestSafeInlineLink(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"[foo](/bar/)\n",
 		"<p><a href=\"/bar/\">foo</a></p>\n",
@@ -583,6 +595,7 @@ func TestSafeInlineLink(t *testing.T) {
 }
 
 func TestReferenceLink(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"[link][ref]\n",
 		"<p>[link][ref]</p>\n",
@@ -621,6 +634,7 @@ func TestReferenceLink(t *testing.T) {
 }
 
 func TestTags(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"a <span>tag</span>\n",
 		"<p>a <span>tag</span></p>\n",
@@ -638,6 +652,7 @@ func TestTags(t *testing.T) {
 }
 
 func TestAutoLink(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"http://foo.com/\n",
 		"<p><a href=\"http://foo.com/\">http://foo.com/</a></p>\n",
@@ -943,12 +958,14 @@ what happens here
 }
 
 func TestFootnotes(t *testing.T) {
+	t.Parallel()
 	doTestsInlineParam(t, footnoteTests, TestParams{
 		extensions: Footnotes,
 	})
 }
 
 func TestFootnotesWithParameters(t *testing.T) {
+	t.Parallel()
 	tests := make([]string, len(footnoteTests))
 
 	prefix := "testPrefix"
@@ -978,6 +995,7 @@ func TestFootnotesWithParameters(t *testing.T) {
 }
 
 func TestNestedFootnotes(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		`Paragraph.[^fn1]
 
@@ -1005,6 +1023,7 @@ func TestNestedFootnotes(t *testing.T) {
 }
 
 func TestInlineComments(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"Hello <!-- there ->\n",
 		"<p>Hello &lt;!&mdash; there &ndash;&gt;</p>\n",
@@ -1034,6 +1053,7 @@ func TestInlineComments(t *testing.T) {
 }
 
 func TestSmartDoubleQuotes(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"this should be normal \"quoted\" text.\n",
 		"<p>this should be normal &ldquo;quoted&rdquo; text.</p>\n",
@@ -1046,6 +1066,7 @@ func TestSmartDoubleQuotes(t *testing.T) {
 }
 
 func TestSmartDoubleQuotesNBSP(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"this should be normal \"quoted\" text.\n",
 		"<p>this should be normal &ldquo;&nbsp;quoted&nbsp;&rdquo; text.</p>\n",
@@ -1058,6 +1079,7 @@ func TestSmartDoubleQuotesNBSP(t *testing.T) {
 }
 
 func TestSmartAngledDoubleQuotes(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"this should be angled \"quoted\" text.\n",
 		"<p>this should be angled &laquo;quoted&raquo; text.</p>\n",
@@ -1070,6 +1092,7 @@ func TestSmartAngledDoubleQuotes(t *testing.T) {
 }
 
 func TestSmartAngledDoubleQuotesNBSP(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"this should be angled \"quoted\" text.\n",
 		"<p>this should be angled &laquo;&nbsp;quoted&nbsp;&raquo; text.</p>\n",
@@ -1082,6 +1105,7 @@ func TestSmartAngledDoubleQuotesNBSP(t *testing.T) {
 }
 
 func TestSmartFractions(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		"1/2, 1/4 and 3/4; 1/4th and 3/4ths\n",
 		"<p>&frac12;, &frac14; and &frac34;; &frac14;th and &frac34;ths</p>\n",
@@ -1100,6 +1124,7 @@ func TestSmartFractions(t *testing.T) {
 }
 
 func TestDisableSmartDashes(t *testing.T) {
+	t.Parallel()
 	doTestsInlineParam(t, []string{
 		"foo - bar\n",
 		"<p>foo - bar</p>\n",
@@ -1135,6 +1160,7 @@ func TestDisableSmartDashes(t *testing.T) {
 }
 
 func TestSkipLinks(t *testing.T) {
+	t.Parallel()
 	doTestsInlineParam(t, []string{
 		"[foo](gopher://foo.bar)",
 		"<p><tt>foo</tt></p>\n",
@@ -1147,6 +1173,7 @@ func TestSkipLinks(t *testing.T) {
 }
 
 func TestSkipImages(t *testing.T) {
+	t.Parallel()
 	doTestsInlineParam(t, []string{
 		"![foo](/bar/)\n",
 		"<p></p>\n",
@@ -1156,6 +1183,7 @@ func TestSkipImages(t *testing.T) {
 }
 
 func TestUseXHTML(t *testing.T) {
+	t.Parallel()
 	doTestsParam(t, []string{
 		"---",
 		"<hr>\n",
@@ -1167,6 +1195,7 @@ func TestUseXHTML(t *testing.T) {
 }
 
 func TestSkipHTML(t *testing.T) {
+	t.Parallel()
 	doTestsParam(t, []string{
 		"<div class=\"foo\"></div>\n\ntext\n\n<form>the form</form>",
 		"<p>text</p>\n\n<p>the form</p>\n",
diff --git a/markdown_test.go b/markdown_test.go
index 2c7a262..078dcda 100644
--- a/markdown_test.go
+++ b/markdown_test.go
@@ -16,6 +16,7 @@ package blackfriday
 import "testing"
 
 func TestDocument(t *testing.T) {
+	t.Parallel()
 	var tests = []string{
 		// Empty document.
 		"",
diff --git a/ref_test.go b/ref_test.go
index 4375f54..a2e689c 100644
--- a/ref_test.go
+++ b/ref_test.go
@@ -20,6 +20,7 @@ import (
 )
 
 func TestReference(t *testing.T) {
+	t.Parallel()
 	files := []string{
 		"Amps and angle encoding",
 		"Auto links",
@@ -48,6 +49,7 @@ func TestReference(t *testing.T) {
 }
 
 func TestReference_EXTENSION_NO_EMPTY_LINE_BEFORE_BLOCK(t *testing.T) {
+	t.Parallel()
 	files := []string{
 		"Amps and angle encoding",
 		"Auto links",