diff --git a/encode.go b/encode.go
index c921835..a45ffd9 100644
--- a/encode.go
+++ b/encode.go
@@ -982,10 +982,10 @@ func (e *encodeState) string(s string, escapeHTML bool) int {
 			e.WriteString(s[start:i])
 		}
 		if c < 0x10000 {
-			e.WriteString(fmt.Sprintf(`\u%04X`, c))
+			fmt.Fprintf(e, `\u%04X`, c)
 		} else {
 			r1, r2 := utf16.EncodeRune(c)
-			e.WriteString(fmt.Sprintf(`\u%04X\u%04X`, r1, r2))
+			fmt.Fprintf(e, `\u%04X\u%04X`, r1, r2)
 		}
 		i += size
 		start = i
@@ -1077,10 +1077,10 @@ func (e *encodeState) stringBytes(s []byte, escapeHTML bool) int {
 			e.Write(s[start:i])
 		}
 		if c < 0x10000 {
-			e.WriteString(fmt.Sprintf(`\u%04X`, c))
+			fmt.Fprintf(e, `\u%04X`, c)
 		} else {
 			r1, r2 := utf16.EncodeRune(c)
-			e.WriteString(fmt.Sprintf(`\u%04X\u%04X`, r1, r2))
+			fmt.Fprintf(e, `\u%04X\u%04X`, r1, r2)
 		}
 		i += size
 		start = i
diff --git a/encode_test.go b/encode_test.go
index fb90013..8387eb0 100644
--- a/encode_test.go
+++ b/encode_test.go
@@ -496,8 +496,8 @@ func TestStringBytes(t *testing.T) {
 		esBytes := &encodeState{}
 		esBytes.stringBytes([]byte(s), escapeHTML)
 
-		enc := es.Buffer.String()
-		encBytes := esBytes.Buffer.String()
+		enc := es.String()
+		encBytes := esBytes.String()
 		if enc != encBytes {
 			i := 0
 			for i < len(enc) && i < len(encBytes) && enc[i] == encBytes[i] {