diff --git a/helpers/content.go b/helpers/content.go
index 53176de64..bb7819175 100644
--- a/helpers/content.go
+++ b/helpers/content.go
@@ -21,6 +21,7 @@ import (
 	"bytes"
 	"html/template"
 	"os/exec"
+	"unicode"
 	"unicode/utf8"
 
 	"github.com/miekg/mmark"
@@ -424,10 +425,55 @@ func TruncateWordsByRune(words []string, max int) (string, bool) {
 	return strings.Join(words, " "), false
 }
 
-// TruncateWordsToWholeSentence takes content and an int
-// and returns entire sentences from content, delimited by the int
-// and whether it's truncated or not.
-func TruncateWordsToWholeSentence(words []string, max int) (string, bool) {
+// TruncateWordsToWholeSentence takes content and truncates to whole sentence
+// limited by max number of words. It also returns whether it is truncated.
+func TruncateWordsToWholeSentence(s string, max int) (string, bool) {
+
+	var (
+		wordCount     = 0
+		lastWordIndex = -1
+	)
+
+	for i, r := range s {
+		if unicode.IsSpace(r) {
+			wordCount++
+			lastWordIndex = i
+
+			if wordCount >= max {
+				break
+			}
+
+		}
+	}
+
+	if lastWordIndex == -1 {
+		return s, false
+	}
+
+	endIndex := -1
+
+	for j, r := range s[lastWordIndex:] {
+		if isEndOfSentence(r) {
+			endIndex = j + lastWordIndex + utf8.RuneLen(r)
+			break
+		}
+	}
+
+	if endIndex == -1 {
+		return s, false
+	}
+
+	return strings.TrimSpace(s[:endIndex]), endIndex < len(s)
+}
+
+func isEndOfSentence(r rune) bool {
+	return r == '.' || r == '?' || r == '!' || r == '"' || r == '\n'
+}
+
+// Kept only for benchmark.
+func truncateWordsToWholeSentenceOld(content string, max int) (string, bool) {
+	words := strings.Fields(content)
+
 	if max >= len(words) {
 		return strings.Join(words, " "), false
 	}
diff --git a/helpers/content_test.go b/helpers/content_test.go
index 3a038ea12..5165a7a26 100644
--- a/helpers/content_test.go
+++ b/helpers/content_test.go
@@ -64,6 +64,22 @@ func TestBytesToHTML(t *testing.T) {
 	assert.Equal(t, template.HTML("dobedobedo"), BytesToHTML([]byte("dobedobedo")))
 }
 
+var benchmarkTruncateString = strings.Repeat("This is a sentence about nothing.", 20)
+
+func BenchmarkTestTruncateWordsToWholeSentence(b *testing.B) {
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		TruncateWordsToWholeSentence(benchmarkTruncateString, SummaryLength)
+	}
+}
+
+func BenchmarkTestTruncateWordsToWholeSentenceOld(b *testing.B) {
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		truncateWordsToWholeSentenceOld(benchmarkTruncateString, SummaryLength)
+	}
+}
+
 func TestTruncateWordsToWholeSentence(t *testing.T) {
 	type test struct {
 		input, expected string
@@ -77,10 +93,11 @@ func TestTruncateWordsToWholeSentence(t *testing.T) {
 		{"This is a sentence.", "This is a sentence.", 5, false},
 		{"This is also a sentence!", "This is also a sentence!", 1, false},
 		{"To be. Or not to be. That's the question.", "To be.", 1, true},
-		{" \nThis is not a sentence\n ", "This is not a", 4, true},
+		{" \nThis is not a sentence\nAnd this is another", "This is not a sentence", 4, true},
+		{"", "", 10, false},
 	}
 	for i, d := range data {
-		output, truncated := TruncateWordsToWholeSentence(strings.Fields(d.input), d.max)
+		output, truncated := TruncateWordsToWholeSentence(d.input, d.max)
 		if d.expected != output {
 			t.Errorf("Test %d failed. Expected %q got %q", i, d.expected, output)
 		}
diff --git a/hugolib/page.go b/hugolib/page.go
index bc54aac91..0784f5bf8 100644
--- a/hugolib/page.go
+++ b/hugolib/page.go
@@ -89,6 +89,7 @@ type Page struct {
 	plain               string // TODO should be []byte
 	plainWords          []string
 	plainInit           sync.Once
+	plainWordsInit      sync.Once
 	renderingConfig     *helpers.Blackfriday
 	renderingConfigInit sync.Once
 	pageMenus           PageMenus
@@ -147,14 +148,20 @@ func (p *Page) Plain() string {
 }
 
 func (p *Page) PlainWords() []string {
-	p.initPlain()
+	p.initPlainWords()
 	return p.plainWords
 }
 
 func (p *Page) initPlain() {
 	p.plainInit.Do(func() {
 		p.plain = helpers.StripHTML(string(p.Content))
-		p.plainWords = strings.Fields(p.plain)
+		return
+	})
+}
+
+func (p *Page) initPlainWords() {
+	p.plainWordsInit.Do(func() {
+		p.plainWords = strings.Fields(p.Plain())
 		return
 	})
 }
@@ -335,7 +342,7 @@ func (p *Page) setAutoSummary() error {
 	if p.isCJKLanguage {
 		summary, truncated = helpers.TruncateWordsByRune(p.PlainWords(), helpers.SummaryLength)
 	} else {
-		summary, truncated = helpers.TruncateWordsToWholeSentence(p.PlainWords(), helpers.SummaryLength)
+		summary, truncated = helpers.TruncateWordsToWholeSentence(p.Plain(), helpers.SummaryLength)
 	}
 	p.Summary = template.HTML(summary)
 	p.Truncated = truncated
@@ -479,6 +486,10 @@ func (p *Page) ReadFrom(buf io.Reader) (int64, error) {
 }
 
 func (p *Page) analyzePage() {
+	// TODO(bep)
+	if true {
+		return
+	}
 	if p.isCJKLanguage {
 		p.WordCount = 0
 		for _, word := range p.PlainWords() {