diff --git a/transform/livereloadinject/livereloadinject.go b/transform/livereloadinject/livereloadinject.go
index a29a64ebb..43c03348d 100644
--- a/transform/livereloadinject/livereloadinject.go
+++ b/transform/livereloadinject/livereloadinject.go
@@ -14,10 +14,10 @@
 package livereloadinject
 
 import (
-	"bytes"
 	"fmt"
 	"html"
 	"net/url"
+	"regexp"
 	"strings"
 
 	"github.com/gohugoio/hugo/common/loggers"
@@ -25,42 +25,27 @@ import (
 	"github.com/gohugoio/hugo/transform"
 )
 
-const warnMessage = `"head" or "body" tag is required in html to append livereload script. ` +
-	"As a fallback, Hugo injects it somewhere but it might not work properly."
-
-var warnScript = fmt.Sprintf(`<script data-no-instant defer>console.warn('%s');</script>`, warnMessage)
-
-type tag struct {
-	markup       []byte
-	appendScript bool
-	warnRequired bool
+var ignoredSyntax = regexp.MustCompile(`(?s)^(?:\s+|<!--.*?-->|<\?.*?\?>)*`)
+var tagsBeforeHead = []*regexp.Regexp{
+	regexp.MustCompile(`(?is)^<!doctype\s[^>]*>`),
+	regexp.MustCompile(`(?is)^<html(?:\s[^>]*)?>`),
+	regexp.MustCompile(`(?is)^<head(?:\s[^>]*)?>`),
 }
 
-var tags = []tag{
-	{markup: []byte("<head"), appendScript: true},
-	{markup: []byte("<HEAD"), appendScript: true},
-	{markup: []byte("</body>")},
-	{markup: []byte("</BODY>")},
-	{markup: []byte("<html"), appendScript: true, warnRequired: true},
-	{markup: []byte("<HTML"), appendScript: true, warnRequired: true},
-}
-
-// New creates a function that can be used
-// to inject a script tag for the livereload JavaScript in a HTML document.
+// New creates a function that can be used to inject a script tag for
+// the livereload JavaScript at the start of an HTML document's head.
 func New(baseURL url.URL) transform.Transformer {
 	return func(ft transform.FromTo) error {
 		b := ft.From().Bytes()
-		idx := -1
-		var match tag
-		// We used to insert the livereload script right before the closing body.
-		// This does not work when combined with tools such as Turbolinks.
-		// So we try to inject the script as early as possible.
-		for _, t := range tags {
-			idx = bytes.Index(b, t.markup)
-			if idx != -1 {
-				match = t
-				break
-			}
+
+		// We find the start of the head by reading past (in order)
+		// the doctype declaration, HTML start tag and head start tag,
+		// all of which are optional, and any whitespace, comments, or
+		// XML instructions in-between.
+		idx := 0
+		for _, tag := range tagsBeforeHead {
+			idx += len(ignoredSyntax.Find(b[idx:]))
+			idx += len(tag.Find(b[idx:]))
 		}
 
 		path := strings.TrimSuffix(baseURL.Path, "/")
@@ -72,23 +57,9 @@ func New(baseURL url.URL) transform.Transformer {
 		c := make([]byte, len(b))
 		copy(c, b)
 
-		if idx == -1 {
-			idx = len(b)
-			match = tag{warnRequired: true}
-		}
-
 		script := []byte(fmt.Sprintf(`<script src="%s" data-no-instant defer></script>`, html.EscapeString(src)))
 
-		i := idx
-		if match.appendScript {
-			i += bytes.Index(b[i:], []byte(">")) + 1
-		}
-
-		if match.warnRequired {
-			script = append(script, []byte(warnScript)...)
-		}
-
-		c = append(c[:i], append(script, c[i:]...)...)
+		c = append(c[:idx], append(script, c[idx:]...)...)
 
 		if _, err := ft.To().Write(c); err != nil {
 			loggers.Log().Warnf("Failed to inject LiveReload script:", err)
diff --git a/transform/livereloadinject/livereloadinject_test.go b/transform/livereloadinject/livereloadinject_test.go
index cba2d3834..dc8740208 100644
--- a/transform/livereloadinject/livereloadinject_test.go
+++ b/transform/livereloadinject/livereloadinject_test.go
@@ -43,32 +43,80 @@ func TestLiveReloadInject(t *testing.T) {
 		return out.String()
 	}
 
-	c.Run("Head lower", func(c *qt.C) {
-		c.Assert(apply("<html><head>foo"), qt.Equals, "<html><head>"+expectBase+"foo")
+	c.Run("Inject after head tag", func(c *qt.C) {
+		c.Assert(apply("<!doctype html><html><head>after"), qt.Equals, "<!doctype html><html><head>"+expectBase+"after")
 	})
 
-	c.Run("Head upper", func(c *qt.C) {
-		c.Assert(apply("<html><HEAD>foo"), qt.Equals, "<html><HEAD>"+expectBase+"foo")
+	c.Run("Inject after head tag when doctype and html omitted", func(c *qt.C) {
+		c.Assert(apply("<head>after"), qt.Equals, "<head>"+expectBase+"after")
 	})
 
-	c.Run("Body lower", func(c *qt.C) {
-		c.Assert(apply("foo</body>"), qt.Equals, "foo"+expectBase+"</body>")
+	c.Run("Inject after html when head omitted", func(c *qt.C) {
+		c.Assert(apply("<html>after"), qt.Equals, "<html>"+expectBase+"after")
 	})
 
-	c.Run("Body upper", func(c *qt.C) {
-		c.Assert(apply("foo</BODY>"), qt.Equals, "foo"+expectBase+"</BODY>")
+	c.Run("Inject after doctype when head and html omitted", func(c *qt.C) {
+		c.Assert(apply("<!doctype html>after"), qt.Equals, "<!doctype html>"+expectBase+"after")
 	})
 
-	c.Run("Html upper", func(c *qt.C) {
-		c.Assert(apply("<html>foo"), qt.Equals, "<html>"+expectBase+warnScript+"foo")
+	c.Run("Inject before other elements if all else omitted", func(c *qt.C) {
+		c.Assert(apply("<title>after</title>"), qt.Equals, expectBase+"<title>after</title>")
 	})
 
-	c.Run("Html upper with attr", func(c *qt.C) {
-		c.Assert(apply(`<html lang="en">foo`), qt.Equals, `<html lang="en">`+expectBase+warnScript+"foo")
+	c.Run("Inject before text content if all else omitted", func(c *qt.C) {
+		c.Assert(apply("after"), qt.Equals, expectBase+"after")
 	})
 
-	c.Run("No match", func(c *qt.C) {
-		c.Assert(apply("<h1>No match</h1>"), qt.Equals, "<h1>No match</h1>"+expectBase+warnScript)
+	c.Run("Inject after HeAd tag MiXed CaSe", func(c *qt.C) {
+		c.Assert(apply("<HeAd>AfTer"), qt.Equals, "<HeAd>"+expectBase+"AfTer")
+	})
+
+	c.Run("Inject after HtMl tag MiXed CaSe", func(c *qt.C) {
+		c.Assert(apply("<HtMl>AfTer"), qt.Equals, "<HtMl>"+expectBase+"AfTer")
+	})
+
+	c.Run("Inject after doctype mixed case", func(c *qt.C) {
+		c.Assert(apply("<!DocType HtMl>AfTer"), qt.Equals, "<!DocType HtMl>"+expectBase+"AfTer")
+	})
+
+	c.Run("Inject after html tag with attributes", func(c *qt.C) {
+		c.Assert(apply(`<html lang="en">after`), qt.Equals, `<html lang="en">`+expectBase+"after")
+	})
+
+	c.Run("Inject after html tag with newline", func(c *qt.C) {
+		c.Assert(apply("<html\n>after"), qt.Equals, "<html\n>"+expectBase+"after")
+	})
+
+	c.Run("Skip comments and whitespace", func(c *qt.C) {
+		c.Assert(
+			apply(" <!--x--> <!doctype html>\n<?xml instruction ?> <head>after"),
+			qt.Equals,
+			" <!--x--> <!doctype html>\n<?xml instruction ?> <head>"+expectBase+"after",
+		)
+	})
+
+	c.Run("Do not search inside comment", func(c *qt.C) {
+		c.Assert(apply("<html><!--<head>-->"), qt.Equals, "<html><!--<head>-->"+expectBase)
+	})
+
+	c.Run("Do not search inside scripts", func(c *qt.C) {
+		c.Assert(apply("<html><script>`<head>`</script>"), qt.Equals, "<html>"+expectBase+"<script>`<head>`</script>")
+	})
+
+	c.Run("Do not search inside templates", func(c *qt.C) {
+		c.Assert(apply("<html><template><head></template>"), qt.Not(qt.Equals), "<html><template><head>"+expectBase+"</template>")
+	})
+
+	c.Run("Search from the start of the input", func(c *qt.C) {
+		c.Assert(apply("<head>after<head>"), qt.Equals, "<head>"+expectBase+"after<head>")
+	})
+
+	c.Run("Do not mistake header for head", func(c *qt.C) {
+		c.Assert(apply("<html><header>"), qt.Equals, "<html>"+expectBase+"<header>")
+	})
+
+	c.Run("Do not mistake custom elements for head", func(c *qt.C) {
+		c.Assert(apply("<html><head-custom>"), qt.Equals, "<html>"+expectBase+"<head-custom>")
 	})
 }
 
